Image source: U.S. Department of State (top left); KCTV (right and bottom left)
Even though the "North Korea policy review" by the new Biden administration has reportedly yet to be concluded,  the month of March 2021 marked the first significant public articulation of positions and signalling by the United States (US) and the Democratic People's Republic of Korea (DPRK) vis-à-vis each other. It has quickly become clear that mutual threat perceptions and diverging understandings of past agreements will continue to make it challenging for the two parties to advance in normalizing relations following the breakdown of talks in Hanoi in 2019.
From 8 to 18 March 2021, the US and the Republic of Korea (ROK) carried out joint military exercises in a downscaled form. Nevertheless, the DPRK issued statements reiterating its long standing view that the joint military exercises are threatening and illegitimate.  It also launched two cruise missiles and two ballistic missiles on 21 and 25 March 2021, respectively.
Both the US and the ROK have downplayed the significance of these activities by the DPRK. Nonetheless, the risk of further deterioration in relations and escalation of tensions remains substantial, particularly given the historically tenuous period following a change in US administration.  Both countries have yet to complete their (re)calibration of relevant key policies, further increasing the risk of misunderstandings as a result of over a year without substantive engagement . This risk is further exacerbated by the DPRK's recent showcasing of new ballistic missiles at a recent military parade on 14 January 2021, as well as the announcement of its intention to continuously bolster national defence capabilities and strengthen nuclear deterrence against the US. 
This report provides a risk assessment related to these developments in March 2021 and highlights key factors that could escalate tensions in the DPRK-US and DPRK-ROK relationships in the near term.
US-ROK Joint Military Exercises and High Level Consultations
The US and the ROK conducted their 2021-1 Combined Command Post Training joint military exercises from 8 to 18 March 2021. Government authorities emphasized that the exercises would be based solely on computer simulations and not feature outside troop manoeuvres. The official reason for downscaling the exercises was attributed primarily to complications related to the COVID-19 pandemic. However, the US and the ROK also referred to their intention not to foreclose opportunities related to the "denuclearization of the Korean Peninsula and the establishment of peace."  Large-scale annual joint exercises have not been conducted since 2018 following an informal understanding between the US and the ROK that such exercises would be halted.
In the concluding days of the March 2021 exercises, US Secretary of State Antony Blinken and Secretary of Defense Lloyd Austin also visited Seoul (17-18 March) for the first time for socalled "2 plus 2" meetings following a similar stop in Japan (16-17 March) and just before a meeting with Chinese officials (18 March). In a joint statement, the US and the ROK "emphasized that North Korean nuclear and ballistic missile issues are a priority for the Alliance" and that they remained "committed to maintain high-level consultations on the United States' ongoing North Korea policy review." 
Nevertheless, some subtle differences in priorities and language were discernible between the statements made by the US and ROK officials. For example, Blinken highlighted that the "authoritarian regime in North Korea continues to commit systemic and widespread abuse against its own people."  As noted by many observers,  he also subtly differed with his ROK counterpart on terminology with regard to "denuclearization". For example, in the joint US-ROK press conference on 18 March 2021, Blinken referred to the continued US objective of "denuclearization of North Korea," which stands in contrast to the preferred formulation of "denuclearization of the Korean Peninsula" by the ROK, as clarified by Foreign Minister Chung Eui-yong in the same press conference.  There was no reference to "denuclearization" as well as no reference to China or a peace regime process in the joint statement, which may suggest that the two parties did not find mutually agreeable language on these issues.
Neither US Secretary Blinken nor ROK Foreign Minister Chung Eui-yong responded directly to the statements issued by Kim Yo Jong and Choe Son Hui on 16 March and 18 March, respectively (see below), only commenting that they were aware of them and that they understood that the DPRK may also be reviewing its policy toward the US. 
DPRK Public Statements on Foreign Relations in March 2021
Starting on 16 March 2021, the DPRK released a series of high-profile official statements during and following the aforementioned events surrounding the joint military exercises and high level consultations. While a denunciation of the US-ROK joint military exercises featured in a number of those statements, a closer reading suggests that they included criticism of US and/or ROK activities beyond the exercises themselves. Although attributed to different officials, and addressed to different audiences, the statements well illustrate the potential difficulties ahead for DPRK-US and DPRK-ROK relations.
Taken together, these statements can be viewed as:
(1) A first response to US and US-allied conduct and the language used by the new US administration on DPRK-related issues; and
(2) Implementation of Kim Jong Un's report during the 8th Workers' Party of Korea (WPK) Congress on the activities of the WPK Central Committee which, among other things, included specific guiding principles for the WPK's external relations.
The statements also highlighted key aspects which the DPRK has long deemed as manifestations of "US hostile policy":
Hostile military posture and exercises (16 March/Kim Yo Jong; 27 March/Ri Pyong Chol; 30 March/Kim Yo Jong);
Insincere diplomacy and unilateral demands (18 March/Choe Son Hui; 30 March/Kim Yo Jong); and
Development-hindering sanctions (19 March/MF; 23 March/MFA; 29 March/Jo Chol Su).
Beyond the longstanding demand for the US to withdraw its "hostile policy" , the statements also provide further insight into what the DPRK currently considers as preconditions for the resumption of dialogue with the US and with the ROK, including:
A change in "future attitude and actions" by the ROK and the understanding that a "war drill and hostility can never go with dialogue and cooperation"; 
Listening to the "meaningful warning that [refraining from joint military exercises] might become the last chance for repairing the north-south relations"; , 
Adjusting public statements to not express a "lunatic theory of "threat from north Korea" and groundless rhetoric about "complete denuclearization" , likely referring to the inconsistency with which US officials have talked about the US objective on "denuclearization" during the first weeks of the Biden administration; 
Creating an "atmosphere for both parties [US and DPRK] to exchange words on an equal basis"; 
Refraining from using engagement channels only as a "means for gaining time and building up the public opinion"; 
Acknowledgment by the US of a new status quo: "It will only be a waste of time to sit with the U.S. as it is not ready to feel and accept new change and new times." 
These points have been consistently highlighted in the DPRK's public statements since the breakdown of talks in the aftermath of the Hanoi Summit in 2019.  Their reiteration at this time, however, suggests that the DPRK has not completely ruled out a resumption of talks. This may also be inferred from the statement by First Vice Minister Choe Son Hui, in which she notes that the DPRK would "counter the U.S. on the principle of power for power and goodwill for goodwill."  This is also in line with the guiding principles provided by Kim Jong Un in his report during the 8th WPK Congress. 
Nevertheless, there are three specific warnings worthy of further attention in the 18 March 2021 statement issued by Vice Department Director Kim Yo Jong. She projects that, without an observable change in attitude and actions - as the "Party Central Committee has already clarified" , the DPRK may move towards:
Possible dissolution of the Committee for the Peaceful Reunification of the Country, a North Korean state entity serving inter-Korean communication and coordination activities;
Possible dissolution of the Kumgangsan International Tourism Bureau and similar interKorean cooperation and exchange organizations;
Possible abrogation of the inter-Korean "Agreement on the Implementation of the Historic Panmunjom Declaration in the Military Domain" (the Comprehensive Military Agreement). 
Following through on these warnings may diminish prospects for a resumption of inter-Korean cooperation and confidence-building projects of recent years. Abrogating the Comprehensive Military Agreement, in particular, would be deemed by the ROK as a major setback in progress made since 2018 following the Panmunjom Declaration, because it is positioned as a key risk reducing achievement on the Korean Peninsula.
In the DPRK statements issued following the short-range ballistic missile launches on 25 March, the DPRK defended its missile related activities as being legitimate and necessary in order to counter the growing conventional military capability of the ROK. This reflects the DPRK's concerns about the ROK's ballistic missiles, as noted by Kim Jong Un in his report during the 8th WPK Congress.  Similarly, Kim Yo Jong's statement of 30 March 2021 criticized the ROK's development of the Hyunmoo-4, which President Moon had lauded as having the world's heaviest warhead.  Given that the ROK is engaged in a multi-year programme of military modernization and the acquisition of highly advanced assets, including a light aircraft carrier and possibly a nuclear-powered submarine,  the ROK and the DPRK are likely to continue to engage in mutual recriminations about the development of advanced conventional assets.
DPRK Missile Launches in March 2021
The DPRK conducted two missile launches on two separate days following the US-ROK joint military exercises and the high-level US/ROK/Japan consultations. Although timed to take place just after joint exercises, the 21 March 2021 firing of the short-range cruise missiles was conducted with a low profile and without DPRK media coverage. The responses of the US and ROK Governments were also subdued, apparently to avoid heightening tensions. On the other hand, the response of the two governments to the 25 March 2021 launch of a short-range nuclear-capable ballistic missile was more openly critical in light of the significance of the event, in particular because it was a violation of UNSC resolutions and because such missiles are perceived as posing a security threat to the region.
Cruise Missile Launches, 21 March 2021
Two short-range cruise missiles were launched by the DPRK off its west coast from the Onchon area, South Pyongan Province, in the early morning of 21 March 2021. At the time of this writing, the DPRK has not reported on these launches and their occurrence was publicly announced only two days later in a Washington Post report and later confirmed by the US and the ROK.  Further information regarding the launches (e.g. type, range, altitude) are not publicly known and were not announced by the US, the ROK or Japan. Based on currently available information about North Korean cruise missiles, there are three possible candidates:
* The KN-01 designation has been widely used to refer to two very different missile systems in the open source literature.
Since 2012, there have been a total of eight publicly known cruise missile launches by the DPRK. The most recent ones, on 14 April 2020 and 21 March 2021, coincided with the period around US-ROK joint military exercises, and the 6 July 2020 firing occurred two days after US Independence Day. None of these firings, however, were publicly reported by the DPRK. It has also been the ROK's practice of not (at least immediately) announcing firings of non-ballistic projectiles, such as the cruise missile launch on 6 July 2020 and the most recent launches on 21 March 2021.
According to ROK Joint Chiefs of Staff officials, the decision not to publicly announce the 21 March 2021 firing was jointly made with the US on the understanding that the non-ballistic and short-range nature of the cruise missiles did not necessitate an immediate public reaction. 
Figure 2: Cruise missile tests conducted by the DPRK, 2012-2021
Ballistic Missile Launches, 25 March 2021
Two short-range ballistic missiles were launched into the sea near Japan’s exclusive economic zone (EEZ) from the area around the DPRK's eastern town of Hamju, South Hamgyong Province, at 7:06 AM and 7:25 AM (GMT+9) on 25 March 2021. According to the DPRK's official statement on the launches, the "two testfired new-type tactical guided missiles accurately hit the target set in the waters 600 km off the east coast of Korea."  According to the ROK's Joint Chiefs of Staff, however, the missiles flew approximately 450 km with an apogee of 60 km.  Similarly, the Japanese Government assesses that the missiles flew approximately 450 km with an apogee of below 100 km, announcing that the missiles had landed outside of Japan's EEZ.  If the missiles had flown for 600 km, as claimed by the DPRK, they would have breached Japan's EEZ and could have achieved a range which can cover almost all territories of the ROK from the launch site.
Figure 3: Official images of the launches suggest that they took place at Yonpo Airfield in Hamju County, which is also where Kim Jong Un oversaw a test of the large caliber KN-25 multiple rocket launcher system on 28 November 2019. EEZ borders are indicated with thin green and red lines. Sources: Google Earth, Flanders Marine Institute, Rodong Sinmun
Figure 4: Left to right: KN-23, KN-24 (both test fired in 2019), new missile test fired on 25 March 2021. While the new missile appears to be a lengthened variant of the KN-23, the nose cone section is more similar to that of a KN-24. Sources: KCNA, KCTV
The new missile is longer than the KN-23 and KN-24 missiles, but still appears to be based on those two systems. The three missiles appear to share similar guidance and control technology and flight profiles. In addition, the DPRK stated that the newly tested missile had the "irregular orbit features of low-altitude gliding leap type flight mode." These so-called "pull-up manoeuvres" were conducted in previous KN-23 and KN-24 launches as also shown by the depicted flight profiles on screens used for monitoring the previous launches (see Figure 5 below). 
Figure 5: In official photos released for the KN-23 and KN-24 launches on 25 July 2019 and 10 August 2019, respectively, depressed trajectories with pull-up manoeuvres can be seen on monitoring screens. Source: Rodong Sinmun, images enhanced by ONN
However, judging from the carrier truck the new missile has no apparent increase in diameter. The truck's width remains unchanged from that of the truck carrying the KN-23 and KN-24 and it can still accommodate two missiles in a very compact manner. It has yet to be ascertained whether the new missile can accommodate the large increase of the payload up to the 2.5 tons, as claimed by the DPRK.  The KN-23 is estimated to have a range of around 600 km with a warhead weighing only around 500 kg, while the KN-24 has a range of around 400 km with a similar warhead weighing only around 500 kg. 
Figure 6: The KN-23 and new missile tested on 25 March 2021 shown in the same carrier truck during a military parade on 14 January 2021. Source: KCTV
Assuming that the payload capacity of the recently launched missile is as claimed by the DPRK, this would suggest that it has a bunker busting penetration capability similar to that of its South Korean counterpart, the Hyunmoo-4 (provided that it has the same accuracy). While South Korean ballistic missiles have demonstrated high accuracy in footage released by the South Korean Ministry of National Defense,  there is no information available to confirm the accuracy of the DPRK's new missiles.
Regardless of whether the new missile is actually deployed as the DPRK's super bunker buster weapon, the new missile does offer a greater conventional capability than the previously tested KN-23 and KN-24. It also has the potential to become a mid-range missile if armed with a lighter, and possibly nuclear, warhead.  The flight test of this new missile, along with its improved solid motor, could contribute to a broader missile development programme that could eventually lead to a solid fuel ICBM.
Further Missile or Nuclear Testing by the DPRK
During the 8th WPK Congress, Kim Jong Un affirmed the DPRK's determination to continue to work on bolstering its military capabilities and its "goal of modernization of the nuclear force." 
This was reiterated in the aforementioned series of official statements in March 2021. Most explicitly, Ri Pyong Chol stated on 27 March that the DPRK is "by no means developing weapons to draw someone's attention or influence his policy" and that it "will continue to increase [its] most thoroughgoing and overwhelming military power."  The DPRK's recent launches in March alone also suggest that research and development on short to longer range missile technology carried out under the Academy of Defence Science is active (though such technology would require considerable testing prior to deployment).
Explosion of the Inter-Korean Liaison Office 2.0
Prior to the demolition of the Inter-Korean Liaison Office in 2020, Kim Yo Jong warned in a statement that closely resembles her more recent one on 18 March 2021 that a shut down of the Liaison Office might occur.
Thus, it is possible that any or all of the following may occur:
Dissolution of the Committee for the Peaceful Reunification of the Country;
Dissolution of the Kumgangsan International Tourism Bureau;
Activities suggesting a complete abrogation of the Comprehensive Military Agreement.
Of particular concern is that the scrapping of the Comprehensive Military Agreement has now been mentioned twice by her alone.
The DPRK has repeatedly expressed its intention to continuously advance its military capabilities that would require further testing. Its historical pattern of missile firings also suggests that further missile tests are possible. The risk that the DPRK might follow through with any or all of the three specific threats issued by Kim Yo Jong on 16 March 2021 should be taken seriously. While recent public statements by both the DPRK and the US illustrate how far apart the two sides still are on core issues, they also suggest that there is a shared view that seeking dialogue under certain conditions could still be in their respective national interests. It remains to be seen whether the parties can find ways to build on this commonality, however small it may appear at present.
 Humeyra Pamuk and Hyonhee Shin, Blinken says U.S. weighs pressure, diplomacy on North Korea over denuclearisation and rights abuses, Reuters, 18 March 2021; Joint Statement of the 2021 Republic of Korea – United States Foreign and Defense Ministerial Meeting ("2+2"), U.S. Department of State, 18 March 2021
 Kim Dong-yeob, 한미 연합군사훈련과 북한의 인식 [Joint ROK-U.S. Military Drills and North Korean Response], Review of North Korean Studies [현대북한연구] 19(2): 83-112, 2016
 Victor Cha, North Korean Provocations Likely Around U.S. Presidential Election, CSIS Beyond Parallel, 23 September 2020
 Steve Holland, White House says U.S. has reached out to North Korea, received no response, Reuters, 15 March 2021
 Katsuhisa Furukawa, The 8th Congress of the Workers’ Party of Korea (1), Open Nuclear Network, 1 February 2021
 S. Korea, U.S. to kick off scaled-back combined exercise this week: JCS, Yonhap News Agency, 7 March 2020
 President Trump News Conference on U.S.-North Korea Summit, C-SPAN, 12 June 2018; Historic First DPRK-U.S. Summit Meeting and Talks Held, KCNA, 13 June 2018
 Defense Department Briefing, C-SPAN, 28 August 2018
 U.S. Military Operations in Asia and the Pacific, C-SPAN, 12 February 2019
 Oh Seok-min, S. Korea to hold springtime combined exercises with U.S as planned: defense chief, Yonhap News Agency, 28 January 2021
 S. Korea, U.S. supposed to stage joint outdoor drills throughout year: defense ministry, Yonhap News Agency, 9 March 2021
 Joint Statement of the 2021 Republic of Korea – United States Foreign and Defense Ministerial Meeting ("2+2"), U.S. Department of State, 18 March 2021
 Secretary Antony J. Blinken and Republic of Korea Foreign Minister Chung Eui-yong Before Their Meeting, U.S. Department of State, 17 March 2021
 Josh Smith, Analysis: Denuclearisation of what? U.S. switch on North Korea wording raises debate, Reuters, 18 March 2021
 Secretary Antony J. Blinken, Secretary of Defense Lloyd Austin, Republic of Korea Foreign Minister Chung Eui-yong, and Republic of Korea Defense Minister Suh Wook at a Joint Press Availability, U.S. Department of State, 18 March 2021; the formulation of "denuclearization of the Korean Peninsula" has also more commonly been used in past UN Security Council resolutions and joint statements between relevant governments; for example in: UNSC Resolution 2375 (2017); the Joint Statement of President Donald J. Trump of the United States of America and Chairman Kim Jong Un of the Democratic People's Republic of Korea at the Singapore Summit from 2018; the Joint Statement of the Fourth Round of the Six-Party Talksfrom 2005; the Joint Declaration on the Denuclearization of the Korean Peninsula from 1992 between the DPRK and the ROK
 Secretary Antony J. Blinken, Secretary of Defense Lloyd Austin, Republic of Korea Foreign Minister Chung Eui-yong, and Republic of Korea Defense Minister Suh Wook at a Joint Press Availability, U.S. Department of State, 18 March 2021
 Spokesperson for Ministry of Foreign Affairs of DPRK Issues Press Statement, KCNA, 6 August 2019
 For example, DPRK Terms U.S. Hostile Policy Main Obstacle in Resolving Nuclear Issue, KCNA, 31 August 2012
 It Will Be Hard to See Again Spring Days Three Years Ago, KCNA, 16 March 2021
 "They are going against the implementation of the north-south agreement on guarantee of peace and military stability in the Korean peninsula in disregard of our repeated warnings that they should stop imports of latest military hardware and joint military exercises with the U.S. … The report seriously warned the south Korean authorities that if they continue to label our action "provocation" with a double-dealing and biased mindset, we have no other choice but to deal with them in a different way." See: Great Programme for Struggle Leading Korean-style Socialist Construction to Fresh Victory - On Report Made by Supreme Leader Kim Jong Un at 8th Congress of WPK, KCNA, 9 January 2021
 Statement of First Vice Foreign Minister of DPRK, KCNA, 18 March 2021
 Analysis: Denuclearisation of what? U.S. switch on North Korea wording raises debate, Reuters, 18 March 2021
 Statement of First Vice Foreign Minister of DPRK, KCNA, 18 March 2021
 For example, by then-Special Envoy Kim Myong Gil in a press statement following an early end to talks with then-Special Representative Stephen Biegun in Sweden, October 2019: "조선반도의 완전한 비핵화는 우리의 안전을 위협하고 발전을 저해하는 모든 장애물들이 깨끗하고 의심할 여지 없이 제거될 때에라야 가능하다는 것입니다. 조선반도 핵 문제를 탄생시키고 그 해결을 어렵게 하고 있는 미국의 위협을 그대로 두고 우리가 먼저 핵 억제력을 포기해야 생존권과 발전권이 보장된다는 주장은 말 앞에 수레를 놓아야 한다는 소리와 마찬가지입니다." ["The complete denuclearization of the Korean Peninsula is only possible when all measures that threaten our safety and impede our development are completely and undoubtedly withdrawn. The assertion that we must first give up our nuclear deterrence to guarantee our right to live and develop while the US threat -which has created the nuclear issue on the Korean Peninsula in the first place and has made it difficult to solve - remains intact, is the same as saying that we ought to put the cart before the horse"] See: 北김명길 순회대사 북미 실무협상 결렬 성명 [DPRK's Ambassador-at-large Kim Myong Gil's statement on the breakdown of DPRK-US working-level talks], Yonhap News Agency, 6 October 2019
 Statement of First Vice Foreign Minister of DPRK, KCNA, 18 March 2021
 "[Kim Jong Un] clarified the stand of the WPK to approach the US on the principle of answering force with toughness and good faith in kind in the future, too, stating that a key to establishing a new relationship between the DPRK and the US lies in the US withdrawal of its hostile policy towards the DPRK." See: Great Programme for Struggle Leading Korean-style Socialist Construction to Fresh Victory - On Report Made by Supreme Leader Kim Jong Un at 8th Congress of WPK, KCNA, 9 January 2021
 It Will Be Hard to See Again Spring Days Three Years Ago, KCNA, 16 March 2021; this is in reference to: "It analysed that the northsouth relations may return to a new starting point of peace and prosperity in the near future, as desired by all compatriots, as they did in the spring three years ago, depending on the south Korean authorities' attitude." See: Great Programme for Struggle Leading Korean-style Socialist Construction to Fresh Victory - On Report Made by Supreme Leader Kim Jong Un at 8th Congress of WPK, KCNA, 9 January 2021
 Agreement on the Implementation of the Historic Panmunjom Declaration in the Military Domain, 19 September 2018
 Most explicitly when demanding that the ROK should give an "explanation for the chief executive's personal remarks … that it had already developed ballistic missiles with the world's heaviest warhead," while at the same time allegedly calling the "development of various conventional weapons, which pertains entirely to our rights, a "provocation." See: Great Programme for Struggle Leading Korean-style Socialist Construction to Fresh Victory - On Report Made by Supreme Leader Kim Jong Un at 8th Congress of WPK, KCNA, 9 January 2021
 Vice-Director of Information and Publicity Department of WPK Central Committee Kim Yo Jong Releases Statement, KCNA, 30 March 2021; cf. Jeffrey Glenn Lewis, South Korea's Hyunmoo-4 and Increasing Missile Capabilities Across Northeast Asia, Datayo.org / ONN, 3 June 2020, available at: https://opennuclear.org/publication/south-koreas-hyunmoo-4-and-increasing-missile-capabilities-across-northeast-asia
 Military finalizes requirement plan for light aircraft carrier, Yonhap News Agency, 30 December 2020; '21-'25 국방중기계획 수립 [Establishment of the 2021-2025 Mid-term Defense Plan], Ministry of National Defense, 10 August 2020; Lami Kim, A Race for Nuclear-Powered Submarines on the Korean Peninsula?, The National Bureau of Asian Research, 31 March 2021
 John Hudson and Ellen Nakashima, North Korea fires short-range missiles in challenge to Biden administration, The Washington Post, 23 March 2021
 N. Korea fired two cruise missiles off west coast Sunday: JCS, Yonhap News Agency, 24 March 2021
 Academy of Defence Science Test-fires New-type Tactical Guided Missiles, KCNA, 26 March 2021
 N. Korea Fires 2 Short-Range Ballistic Missiles into East Sea: JCA, Yonhap News Agency, 25 March 2021
 North Korea fires 2 ballistic missiles into Sea of Japan, Kyodo News, 25 March 2021
 cf. United Nations, S/2020/151, annex 59
 Academy of Defence Science Test-fires New-type Tactical Guided Missiles, KCNA, 26 March 2021
 The estimate for the KN-23's performance is largely based on that of the Iskander, as they share similar size, shape and flight profile. For example: Michael Elleman, North Korea's New Short-Range Missiles: A Technical Evaluation, 38 North, 9 October 2019
 [국방부] 국과연 신형 탄도미사일 시현 영상 (ADD 제공) [[Ministry of National Defense] Demonstration Video of the Agency for Defense Development’s New Ballistic Missiles (ADD Production)], ROK Ministry of National Defense, 29 July 2017, available at: https://www.youtube.com/watch?v=Edr8woqAyuY
 The DPRK's continued objective to work on "smaller and lighter [nuclear warheads] for more tactical uses" was also reiterated by Kim Jong Un during the 8th WPK Congress in January 2021. See: Great Programme for Struggle Leading Korean-style Socialist Construction to Fresh Victory - On Report Made by Supreme Leader Kim Jong Un at 8th Congress of WPK, KCNA, 9 January 2021
 Bernhardt and Sukin also found that US-ROK exercises have a statistically significant effect on the occurrence of military actions by the DPRK. See: Jordan Bernhardt and Lauren Sukin, Joint Military Exercises and Crisis Dynamics on the Korean Peninsula, Journal of Conflict Resolution: 1-34, 2020. Cha, Lee and Lim have found, however, that at least in the years of 2005-2016, USROK exercises did not impact diplomatic relations between the US and DPRK. See: Victor Cha, Na Young Lee and Andy Lim, DPRK Provocations and US-ROK Military Exercises, CSIS Beyond Parallel, 18 August 2016
 Excluding the year of 2013, when no missile tests were conducted during, before or after joint exercises.
 Third Plenary Meeting of Seventh C.C., WPK Held in Presence of Kim Jong Un, KCNA, 21 April 2018
 Great Programme for Struggle Leading Korean-style Socialist Construction to Fresh Victory - On Report Made by Supreme Leader Kim Jong Un at 8th Congress of WPK, KCNA, 9 January 2021; Katsuhisa Furukawa, The 8th Congress of the Workers' Party of Korea (1), Open Nuclear Network, 1 February 2021
 Ri Pyong Chol Expresses Deep Concern over U.S. President's Statement Faulting DPRK's Regular Testfire, KCNA, 27 March 2021
 Barbara Starr, US Has Assessed North Korea Could be Preparing to Carry out First Weapons Test Since Biden Took Office, CNN, 17 March 2021
 Jeffrey Lewis, New Construction at Yondoktong, Armscontrolwonk.com, 2 March 2021; Zachary Cohen and Kylie Atwood, New Satellite Images Reveal North Korea Took Recent Steps to Conceal Nuclear Weapons Site, CNN, 2 March 2021; Ankit Panda, Kim Jong Un and the Bomb: Survival and Deterrence in North Korea, Oxford University Press, 2020, chapter 9
 Kim Yo Jong Blasts Chongwadae's Foolish Way of Thinking, KCNA, 3 March 2020
 Kim Yo Jong Rebukes S. Korean Authorities for Conniving at Anti-DPRK Hostile Act of "Defectors from North", KCNA, 4 June 2020