South Korea-Ukraine Diplomatic Conflict over the Disclosure of North Korean POW Repatriation and an Analysis of the Reality of North Korea-Russia Military Cooperation

Executive Summary

President Zelenskyy's disclosure of the repatriation of North Korean prisoners of war (POWs) during his UN General Assembly speech sparked controversy over the violation of a confidential agreement, escalating into a diplomatic conflict between South Korea and Ukraine. The root cause of the conflict lies in the divergent perceptions of the POW issue: Ukraine viewed it as an asset for its public relations campaign against Russia, while South Korea regarded it as a matter of humanitarian and security management. At the same time, this incident demonstrates that the military alignment between North Korea and Russia—characterized by the combat use of North Korean KN-23 missiles and the deployment of North Korean troops—has entered a phase of concrete physical evidence. Domestically, a structural problem has emerged as the ruling and opposition parties consume this issue as fodder for political strife, sidelining the practical task of protecting the custody of the POWs. The South Korean government needs to adopt a two-track response that separates its demand for an apology from Ukraine from the maintenance of working-level cooperation, while pursuing a utility-oriented strategy that incorporates intelligence on North Korea-Russia military cooperation into the review of the ROK-U.S. combined defense posture.

I. Analysis of the Issue

Issue Analysis: South Korea-Ukraine Diplomatic Conflict over the Disclosure of North Korean POW Repatriation

1. Background and Developments

The North Korean POW issue traces back to early 2025, during the Ukrainian military's offensive into Russia's Kursk region. At the time, Ukrainian forces captured two North Korean soldiers who were supporting Russia [12]. Immediately after their capture, they reportedly expressed their refusal to be repatriated to North Korea [15]. In his speech at the UN General Assembly, President Zelenskyy mentioned that one of them attempted suicide the moment he realized he was being captured [1].

This incident is an extension of the North Korea-Russia military alignment that has been underway since the Vostochny summit in September 2023 [2][4]. In March 2024, Russia vetoed the renewal of the mandate for the UN Security Council's Panel of Experts monitoring sanctions on North Korea, effectively neutralizing the existing sanctions monitoring system [2]. The Treaty on Comprehensive Strategic Partnership, signed in June of the same year, upgraded bilateral relations to a de facto alliance [2][4]. Subsequently, the use of North Korean-made KN-23 series missiles in Russian airstrikes on Kyiv and Zaporizhzhia was cross-verified by multiple independent media outlets [6]. Ukraine's Main Directorate of Intelligence (GUR) and French intelligence authorities independently confirmed the deployment of North Korean missile units in western Russia [6]. The presence of the two POWs serves as physical evidence that this North Korea-Russia military cooperation is proceeding simultaneously along two tracks: troop deployment and the combat deployment of weapon systems.

The governments of South Korea and Ukraine have been conducting confidential consultations regarding the custody and handling of the POWs. The South Korean Presidential Office stated that it had received prior notice from Ukraine that President Zelenskyy's UN speech might include references to the POWs. However, it explained that the level of detail and the manner of expression were not clearly communicated [7]. This suggests that while the two countries attempted prior coordination, they failed to reach an agreement on the extent of the disclosure.

2. Current Situation

During his keynote address at the high-level segment of the UN General Assembly in New York on September 23 (local time), President Zelenskyy disclosed, "We recently sent two North Korean POWs to the Republic of Korea" [12]. The South Korean Ministry of Foreign Affairs stated that it could not confirm "whether, when, or how individual personnel were transferred, or the specific details of the consultations." This was widely interpreted as a de facto acknowledgment of the repatriation [1]. The following day, Representative Yu Yong-weon of the People Power Party added during a National Assembly press conference that the two POWs had departed Ukraine, traveled through a third country, and arrived in South Korea three to four days prior, and that intelligence authorities were currently securing their custody [5][10].

On September 24, President Lee Jae-myung expressed regret over Ukraine's violation of the confidential agreement by disclosing the repatriation to the world [9][14]. The Presidential Office subsequently maintained a cautious stance, repeatedly emphasizing the need to handle the matter in accordance with international law and humanitarian principles [17]. The conflict intensified again on September 27. When the press office of the Ukrainian Presidential Office claimed that no confidential agreement had ever existed, the South Korean Presidential Office defined this as "false public relations" and demanded an official explanation and apology [18][19]. Sung Ki-hong, Senior Secretary to the President for Public Communication, stated, "We express strong regret over the Ukrainian government's unilateral disclosure in violation of the agreement, followed by its false public relations claiming that no confidential agreement existed" [18]. He added, "We are reviewing additional necessary measures" [18]. This suggests that beyond protests through diplomatic channels, measures that could practically impact bilateral relations are also being considered.

Qatar's Al Jazeera reported on the issue internationally, describing it as a souring of bilateral relations between South Korea and Ukraine [11]. The Diplomat assessed that the political fallout regarding the future disposition of the POWs is far from over [15]. This demonstrates that the conflict has transcended a bilateral diplomatic issue and is being consumed by the international community as an opportunity to reaffirm the reality of North Korea-Russia military cooperation.

3. Key Actors and Their Positions

The Ukrainian Government (President Zelenskyy)continued its practice of utilizing the disclosure of battlefield information as a tool in its international public relations campaign against Russia. By revealing the involvement of North Korean troops on the stage of the UN General Assembly, the largest multilateral diplomatic forum, Ukraine is interpreted as intending to impress upon the international community that Russia's war effort relies on the forces of a third country, namely North Korea [12]. However, in this process, Ukraine effectively nullified its separate confidential agreement with South Korea and subsequently damaged South Korea's trust by issuing a public relations statement that denied the existence of the agreement itself [18][19].

The South Korean Presidential Office and Governmenthave maintained the principle that the custody of the POWs should be handled confidentially from the "perspective of human rights and national interest" [3]. The Presidential Office is taking issue with Ukraine's unilateral disclosure and subsequent denial of the agreement, rather than the fact of the repatriation itself. This goes beyond a simple diplomatic discourtesy and has the potential to raise concerns about the reliability of information-sharing and consultation channels with Ukraine on similar sensitive matters in the future.

South Korean Ruling and Opposition Partieshave converted this issue into fodder for domestic political strife. The Democratic Party of Korea expressed regret to Ukraine, stating, "Despite the confidential agreement between South Korea and Ukraine, President Zelenskyy disclosed the repatriation of North Korean POWs to the world," and calling it "an act that betrayed bilateral trust and a dangerous move in terms of national security" [8]. At the same time, the party urged the opposition party to exercise restraint and stop politicizing the issue [8][13]. Conversely, the People Power Party launched an offensive using the frame that the government concealed the repatriation out of concern for "Kim Jong-un's feelings" [3][13]. President Lee Jae-myung strongly refuted this, stating, "Those who harm someone's life, the national interest, and security for their own petty interests are called murderers or traitors" [13]. This demonstrates how the POW issue, which is a security and humanitarian matter, is being consumed within the framework of ruling-opposition confrontation.

North Koreahas not issued any official response to this matter. However, the fact that the two POWs expressed their intent to defect and are currently in South Korea is being received by the international community as a case that reveals the reality of the North Korean military's involvement in the war against Russia and the actual attitudes of its soldiers [15].

4. Key Points of Contention

The first issue is the existence of the confidential agreement and the locus of responsibility for its violation. While the South Korean side asserts that a clear agreement was in place, the press office of the Ukrainian Presidential Office denied the existence of the agreement itself [18][19]. If this gap is not bridged, the trust issue between the two countries could weigh heavily on overall future cooperation beyond this specific case.

The second issue is whether the timing and manner of the disclosure were appropriate. The South Korean government maintains that confidentiality should have been preserved, citing the personal safety of the POWs, the well-being of their families remaining in North Korea, and the potential repercussions on the Korean Peninsula situation [3][8]. Ukraine appears to have chosen disclosure, viewing it as part of its international public relations campaign against Russia, and South Korea's objection is that its position was not sufficiently reflected in this decision-making process.

The third issue is that this case is serving as an opportunity to highlight the reality of North Korea-Russia military cooperation. Coupled with separately verified facts, such as the estimated deployment of over 12,000 North Korean troops and the combat use of KN-23 missiles [2][4][6], the POW issue has the potential to transcend a simple diplomatic discourtesy and lead to discussions on reassessing the security posture on the Korean Peninsula. However, because the sources for figures regarding the scale of the troop deployment remain partly unclear, caution is required to distinguish verified facts from unverified estimates [6].

II. In-Depth Analysis of the Issue

In-Depth Analysis: South Korea-Ukraine Diplomatic Conflict over the Disclosure of North Korean POW Repatriation

1. Analysis of the Root Causes

The superficial cause of this conflict is clear: Ukraine violated the confidential agreement and disclosed the repatriation of the POWs [9][14]. Beneath the surface, however, lies a structural problem: the two countries perceive this issue as fundamentally different political assets.

For President Zelenskyy, North Korean POWs are material for an international public relations campaign. Since the 2022 invasion, Ukraine has consistently pursued a strategy of highlighting Russia's international isolation to sustain Western military and financial support. The involvement of North Korean troops and the combat use of KN-23 missiles are materials that reinforce the narrative that Russia is drawing in allies even within the international sanctions regime [6]. Disclosing the transfer of the POWs on the stage of the UN General Assembly's high-level segment, a platform of maximum exposure, is an extension of this narrative strategy [12]. Revealing details such as the POWs volunteering to go to South Korea, and that one of them attempted suicide the moment he was captured, can be read as an intention to simultaneously highlight the oppressive nature of the North Korean regime and the inhumane plight of those siding with Russia [1].

For the South Korean government, this issue carries the exact opposite implications. The Presidential Office defined the handling of the POWs' custody as a sensitive matter to be addressed from the 'perspective of human rights and national interest' [3]. The government's logic is that if the repatriation is disclosed, the safety of the POWs' families remaining in North Korea could be threatened, and the repercussions on inter-Korean relations and the situation on the Korean Peninsula must be managed [8]. This aligns with the South Korean government's long-standing working practice in handling issues related to North Korean defectors. In short, the root cause of this conflict is a fundamental mismatch in perception: for President Zelenskyy, disclosure was a strategic asset, whereas for the South Korean government, confidentiality was a safeguard.

Added to this was the failure of prior coordination. The Presidential Office stated that it had received prior notice from Ukraine that the speech might include references to the POWs. However, as seen in the explanation that 'it was unclear whether it would be expressed,' no agreement had been reached on the level of disclosure [7]. In effect, the two countries interpreted the situation as they saw fit based on different assumptions, leading to a clash on the stage of the UN General Assembly.

2. Structural Context

Political Structure: Spillover into Domestic Political Strife

This issue was immediately converted into a subject of partisan dispute in South Korean domestic politics. The People Power Party framed the situation as the government concealing the repatriation 'so as not to upset North Korea' [3][8]. The Democratic Party defined this as an 'escalation of political strife' and focused on Ukraine's violation of the agreement [8][13]. President Lee Jae-myung even used strong language against the opposition party, describing them as 'those who harm someone's life, the national interest, and security for their own petty interests' [13]. The structure in which diplomatic issues are immediately absorbed into domestic political strife frames reaffirms the unique sensitivity that North Korean defectors and humanitarian issues related to North Korea hold in South Korean politics. This structure is also evident in the fact that the debate centered on who knew what and when, and what was concealed, rather than the practical issue of the safety and custody of the two POWs.

Security Structure: Physical Evidence of North Korea-Russia Alignment

The broader implication of this incident is that North Korea-Russia military cooperation has transitioned from an abstract concern to concrete physical evidence. The North Korea-Russia alignment that has progressed since the September 2023 Vostochny summit was institutionalized through the neutralization of the sanctions monitoring system in March 2024 and the signing of the Treaty on Comprehensive Strategic Partnership in June of the same year [2][4]. Subsequently, the combat use of KN-23 missiles was cross-verified by multiple media outlets, and the GUR and French intelligence authorities independently confirmed the deployment of North Korean missile units in western Russia [6]. The presence of the two POWs is the final piece of this puzzle. It provides human evidence that the two pillars—troop deployment and weapon system exports—are combined on the actual battlefield. This aligns with existing assessments that 'the practical benefit North Korea gains from troop deployment is not economic compensation, but rather combat data and the verification of precision-guidance technology' [4].

Diplomatic Structure: Asymmetric Interests

South Korea and Ukraine do not possess equal bargaining power in this matter. Ukraine is in desperate need of Western support to sustain the war, and raising international awareness is a key means of securing that support. South Korea, while refraining from providing direct lethal weapons to Ukraine, has maintained engagement focused on humanitarian aid and information sharing [4][6]. In this asymmetric structure, Ukraine has a relatively strong incentive to prioritize the public relations effect on the UN stage over bilateral trust with South Korea, which can be seen as a background factor in this incident.

3. Historical Precedents and Comparison with Similar Cases

The clash between the practice of confidentiality and the risks of disclosure surrounding the custody of North Korean defectors and POWs is not an uncommon phenomenon in South Korean diplomacy. In the past, such as during the issue of the forced repatriation of North Korean defectors in China or inter-Korean contacts through Panmunjom, the government consistently adhered to the principle of confidentiality for the safety of the individuals involved. What makes this case unusual is that the principle of confidentiality was broken by the decision of a third country—Ukraine—which lies outside South Korea's sphere of control. In past cases, the decision to disclose was typically made based on the South Korean government's internal judgment or through direct inter-Korean channels. This time, however, the limits of South Korea's control were clearly revealed, as Ukraine, a party to the war and a key actor in international public relations, unilaterally decided on the disclosure.

In terms of disclosing the reality of North Korea-Russia military cooperation, this case exhibits a pattern similar to the previous confirmation of the combat use of KN-23 missiles [6]. When the actual use of the missiles was confirmed, local intelligence sources, including Ukraine's GUR, disclosed the facts first, leaving South Korea in the position of a recipient verifying the information [6]. This disclosure of the POWs repeated the same dynamic, with Ukraine seizing the initiative in information disclosure and South Korea reacting after the fact. This reaffirms the structural limitation wherein South Korea remains on the periphery of intelligence production, despite being in a position that is most directly affected by the repercussions of North Korea-Russia military cooperation without being a direct party to it.

It also connects to the precedent where President Zelenskyy publicly presented unverified figures regarding the scale of additional North Korean troop deployments [2][4]. At that time, a pattern emerged where information originating from Ukraine circulated in international public opinion before South Korea could make its own policy judgments. The disclosure of the POWs can be seen as a result of this pattern extending to human-related matters.

4. Key Variables Shaping Future Developments

The first variable is the subsequent attitude of the Ukrainian Presidential Office. In response to the claim by the press office of the Ukrainian Presidential Office that no confidential agreement existed, the South Korean Presidential Office defined this as "false public relations" and demanded an official explanation and apology [18][19]. How Ukraine responds to this demand will determine the short-term trajectory of bilateral relations. If an apology or expression of regret is issued, the conflict is likely to be resolved early. Conversely, if Ukraine adheres to its existing position, a cooling effect could ripple through South Korea's working-level channels for humanitarian aid and information-sharing cooperation with Ukraine.

The second variable is the domestic treatment and custody safety of the two POWs. With intelligence authorities reportedly securing their custody [10], how the process of determining their legal status and the safety of their families remaining in North Korea are managed will dictate the humanitarian dimension of this issue. In this process, further information leaks or North Korea's reaction could emerge as new variables.

The third variable is the duration and intensity of South Korea's domestic political strife. If the ruling and opposition parties continue to consume this issue through the frames of government accountability and security, the government's capacity to respond may be exhausted by domestic political defense rather than managing external conflict [3][8][13]. This would also indirectly affect the speed of resolving the conflict with Ukraine.

The fourth variable is whether additional physical evidence of North Korea-Russia military cooperation emerges. Apart from the POW issue, if further verified military facts—such as the deployment of missile units or improvements in impact accuracy—are confirmed [4][6], this POW disclosure incident will be reexamined not as a one-off diplomatic conflict, but as part of a larger trend leading to discussions on reassessing the security posture on the Korean Peninsula.