South Korean President Lee Jae-myung said on Friday that Seoul will take "further measures" if Ukraine continues to refuse a public apology over its disclosure that two captured North Korean soldiers had been sent to South Korea. Lee made the warning on X, saying the matter concerns "the dignity of the Republic of Korea and its people" and cannot be overlooked.

The dispute began last week, when Ukrainian President Volodymyr Zelenskyy revealed the transfer in remarks at the United Nations. The two men were captured by Ukrainian forces early last year, after being deployed with thousands of other North Korean troops to support Russia's war against Ukraine. Seoul says both sides had reached a "clear understanding" in consultations to keep the transfer confidential, and accuses Kyiv of breaching it. Ukraine has denied that any confidentiality agreement existed. Lee said this made him out to be a "liar."

South Korean officials argue that secrecy was meant to protect the soldiers' relatives, since North Korea is known to retaliate against defectors and their families. Both men can be identified because South Korean media photographed them before they arrived in the South. Lee also objected that, when asked to acknowledge the agreement and apologise, Ukraine instead pointed to the possibility of an imminent inter-Korean military conflict. He accused Kyiv of trying to bring "war on the Korean Peninsula." His remarks followed a post by Kyrylo Budanov, Zelenskyy's chief of staff, who referred to a recent landmine incident on the Korean border and wrote that a "trigger event" could lead to "uncontrollable consequences."

Ukrainian Foreign Minister Andrii Sybiha took a softer line in an interview published Thursday, calling the affair a "diplomatic misunderstanding" rather than an incident. He described South Korea as an important partner and said he hoped cooperation would continue. South Korean sources said the next step could be recalling Ambassador Park Ki-chang in protest, and Lee's adviser for peace diplomacy, Song Young-gil, indicated this would follow if Kyiv does not respond to a complaint lodged with Ukraine's envoy in Seoul.

Seoul's spy agency has suggested, according to a lawmaker, that Zelenskyy may have gone public to build support in South Korea for arms deliveries to Ukraine. South Korea, now a major arms exporter, has so far declined to send lethal weapons to Kyiv, citing its policy of not arming countries in active conflicts. Analysts also note that confidentiality may have partly served Ukraine, since publicity could complicate its own prisoner exchanges with Russia.

The row also carries domestic weight. Shin Yul, a political science professor at Myongji University, said the government's swift response to Ukraine contrasts with its caution over the North Korean landmine incident that injured South Korean soldiers, a gap that could leave the public dissatisfied given the administration's dovish approach to nuclear-armed North Korea.