Ukrainian reports of South Korean fuel exports to Russia come amid strained tensions between Seoul and Kyiv.

South Korea’s Ministry of Foreign Affairs has said the government will take legal action over illegal fuel shipments to Russia if allegations from an adviser to Ukrainian President Volodymyr Zelenskyy are confirmed.

The Foreign Ministry said on Thursday it had not confirmed whether South Korean fuel, including diesel, had been exported to Russia.

It added that exports of some products, such as diesel and jet fuel for commercial purposes, were not included in a South Korean exports control list to Russia.

On Wednesday, the South Korean presidential office dismissed a statement by Vladyslav Vlasiuk, an adviser to the Ukrainian president on sanctions policy, that 176,000 tonnes of fuel were shipped from South Korea to Russia via sanctioned tankers in July and August.

Ukraine’s top sanctions official said the alleged findings run counter to South Korea’s sanctions policy towards Russia.

“Since Russia’s invasion of Ukraine, our government has consistently implemented sanctions and export controls against Russia in close cooperation with the international community,” South Korean presidential spokesperson Kang Yu-jung said on Wednesday, according to the Yonhap news agency.

“We ask that Ukraine also refrain from distorting the relevant policies of the Republic of Korea without sufficient verification of the facts and making public remarks that can damage international trust,” she added.

Relations between South Korea and Ukraine have been strained for the past couple of weeks after Seoul accused Zelenskyy of having “unilaterally disclosed” to the United Nations General Assembly that Kyiv had transferred two North Korean prisoners of war to South Korea.

Seoul Korea demanded an official apology from Kyiv, claiming the Ukrainian president had breached a non-disclosure agreement. Kyiv said no such agreement was in place.

Pyongyang and Moscow, meanwhile, have deep ties, with the two countries having signed a mutual defence treaty in 2024. According to Ukrainian and South Korean estimates, about 14,000 to 15,000 North Korean soldiers were sent to support Russia’s war efforts against Ukraine.

North Korea and South Korea remain technically at war because the 1950–1953 Korean War ended in an armistice rather than a peace treaty.