Ukrainian President Volodymyr Zelensky has said he is willing to release North Korean soldiers captured by Ukraine in the Kursk region of Russia in exchange for Ukrainian soldiers being held captive in Russia.

North Korean soldiers sent to bolster Moscow’s forces after Ukraine launched a lightning-fast incursion and seized territory in Russia’s Kursk region over the summer.

Ukraine captured two wounded North Korean soldiers who were fighting on behalf of Russia in a Russian border region, South Korea’s intelligence service said.