According to the statement, Ukraine later disclosed the transfer in President Volodymyr Zelenskyy’s address to the United Nations General Assembly without sufficient prior consultation and subsequently denied the existence of any confidentiality agreement.
Seong said the denial had seriously damaged trust between the two governments and could harm bilateral relations.
Ukraine’s embassy in Seoul did not immediately respond to a Reuters request for comment.
Zelenskyy told the UN General Assembly last week that Ukraine had transferred two captured North Korean soldiers to South Korea. He said the men had recently been sent there after being captured while fighting for Russia in the war against Ukraine.
South Korean President Lee Jae Myung days earlier said Ukraine had disclosed the transfer in breach of a non-disclosure agreement.
In a post on X, Lee said “it was appropriate in every aspect not to disclose” the transfer, given the potential consequences, and that the two sides had agreed to keep it confidential.
“I do not know what circumstances led the Ukrainian side to disclose the matter despite the confidentiality agreement, but it is deeply regrettable,” he wrote.
Ukraine captured the two North Koreans in Russia’s Kursk region in January 2025. They were the first North Korean soldiers to be captured alive since Pyongyang entered the war in 2024, assisting Russia.
South Korea had previously declined to confirm the soldiers’ arrival, citing concerns for their safety and that of family members still in North Korea.
Seoul and Kyiv had been discussing a possible transfer after the two soldiers expressed a desire to go to South Korea, according to an opposition lawmaker in Seoul.
The transfer comes as South Korea has backed efforts to revive dialogue with North Korea, while US President Donald Trump has renewed his willingness to engage with Pyongyang.
