Seoul (AFP) - South Korea’s presidential office has demanded an apology from Ukraine for denying an agreement to keep the transfer of two North Korean prisoners of war to Seoul confidential.

Ukrainian President Volodymyr Zelensky disclosed last week that his country had sent two North Korean soldiers to the South, saying they were “not easy to capture alive”.

The intensifying dispute risks complicating Kyiv’s efforts to obtain weapons from allies including South Korea to fight off bombardments from Russia.

Hours after Zelensky’s remarks at the United Nations, South Korea’s President Lee Jae Myung expressed his dismay.

“I do not know why the Ukrainian side broke the agreement and made the matter public, but it is very disappointing,” he wrote on X.

Seoul said confidentiality was key to protect the POWs’ relatives from any repercussions in North Korea.

“The families left behind in the North could face severe punishment,” Cho Seong-ryoul, a former policy adviser to the presidential national security office, told AFP.

Seoul’s foreign ministry, in a statement to AFP on Monday, said that “as the matter concerns the personal safety of the individuals involved and their families, the two sides had agreed to handle it confidentially”.

Zelensky’s aide Dmytro Lytvyn sought to play down the disclosure, saying that the president did not share any personal details.

Ukraine is an “open country” and it would be unusual to hand over the prisoners in secret, he added.

But Seoul condemned what it viewed as a breach of trust, noting that Zelensky’s press office had denied there was a confidentiality agreement.

That “false statement… seriously undermines trust between the two governments and gravely damages friendly relations between the two countries”, said Seong Ghi-hong, senior presidential secretary for public relations.

The South Korean presidential office demands “an official explanation and apology”, Seong said in a statement late Sunday, adding that Seoul was “considering additional measures that may be necessary regarding this matter”.

- ‘Backlash’ -

Ukraine captured the two North Korean soldiers early last year among Pyongyang’s troops fighting for Moscow.

One of them told South Korean media he was conscripted aged 17 and had served in a reconnaissance unit.

A South Korean lawmaker had previously said the pair wanted to live a “normal life” in the South.

Park Won-gon, a professor at Ewha Womans University in Seoul, said Kyiv’s disclosure may have sparked concern that it could feed into Pyongyang’s hostility towards South Korea.

Since taking power in June 2025, Lee has reversed the stance of his hawkish predecessor Yoon Suk Yeol, offering nuclear-armed Pyongyang talks without preconditions.

The South Korean president “appears to be taking a ‘low-key’ approach as he is mindful of a possible backlash from North Korea,” said Park.

“North Korea has been using the deployed soldiers to create a heroic narrative for regime propaganda, and the South Korean government appears concerned that confirming the prisoners’ return to the South and publicising it could further fuel hostility towards Seoul,” he said.

Beyond the ramifications within South Korea, the row also risks complicating Kyiv’s requests to the ally for armaments supplies.

South Korea has so far not provided lethal weapons to Ukraine, citing a domestic ban on militarily aiding countries at war.

Nevertheless, it had been considering requests for defensive weapons, especially since North Korea deployed troops to support Russia.

The incident “has dealt a significant blow to the relationship of trust between South Korea and Ukraine,” Lim Eul-chul, a professor at Kyungnam University, told AFP.