A North Korean soldier who was captured while fighting in Russia's war against Ukraine has died of his wounds, South Korea's spy agency said Friday. Pyongyang has deployed thousands of troops to reinforce Russia's military, including in the Kursk border region where Ukraine mounted a shock border incursion in August.

There are risks of North Korea sending additional troops and military equipment to the Russian army,” Zelensky said. “We will have tangible responses to this.”

North Korea is preparing to deploy additional troops and weapons, including kamikaze drones, to aid Russia in its full-scale war against Ukraine, the South Korean military said on Dec. 23. Thousands of North Korean personnel are already stationed in Russia.