South Korea's President’s Lee Jae Myung’s office demanded an apology from Ukraine for denying an agreement to keep the transfer of two North Korean prisoners of war from its territory to Seoul confidential.
The row was ignited by Ukrainian President Volodymyr Zelenskyy's disclosure last week that his country had sent two North Korean soldiers to the South, adding that 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 disclosure, South Korea's President Lee Jae Myung criticised the action.
"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.
Zelensky's aide Dmytro Lytvyn sought to play down the disclosure, saying that the president had only made public the fact that the soldiers were handed to South Korea. Ukraine is an "open country", noted Lytvyn, saying that it would be “unusual” to hand over the soldiers in secret.
But Seoul condemned it as a breach of trust.
Seong Ghi-hong, senior presidential secretary for public relations, said in a statement late on Sunday that South Korea was "considering additional measures that may be necessary regarding this matter".
"It is in itself a very serious matter that the Ukrainian side violated the confidentiality agreement between the two countries and made the disclosure unilaterally,” he said.
"But the Ukrainian presidential press office's false statement that there had been no confidentiality agreement, seriously undermines trust between the two governments and gravely damages friendly relations between the two countries," he added.
The South Korean Presidential office demands "an official explanation and apology," said Seong.
Ukraine captured early last year two North Korean soldiers among Pyongyang's troops fighting for Moscow. One of them said he served in a reconnaissance unit and while some North Korean soldiers had been trained to use Russian military equipment, he had not.
The soldier said he was conscripted to the military aged 17 and had been serving since then. A South Korean lawmaker had previously said the pair wanted to live a "normal life" in the South of the Peninsula.
Analysts believe Lee Jae Myung’s angry reaction to the confidentiality agreement risks sparking intense feuds with the nuclear-armed north, which could translate into further hostility towards Seoul.
"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," said Park Won-gon, a professor at Ewha Womans University.
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.
