Ukraine’s President Volodymyr Zelensky says several “seriously wounded” North Korean soldiers died from their injuries after being captured by Ukrainian forces.

“Our soldiers managed to take them prisoner. But they were very seriously wounded and could not be resuscitated,” Zelensky said in an address yesterday.

He did not specify how many soldiers had been captured. The soldiers are believed to be the first North Koreans taken as prisoners of war by Ukraine.

South Korea’s spy agency said earlier that one wounded North Korean soldier, who was captured by Ukraine, had died from his injuries, Yonhap news agency reported.

CNN has reached out to South Korea’s National Intelligence Service and Ukrainian authorities for comment.

Ukraine launched its lightning incursion into Kursk in August, forcing Russia to divert troops to counter the threat.

Zelensky said that the North Korean military has been facing severe losses and accused Russia of sending them to the battlefield with “minimal protection.”

“They have a lot of losses. A lot. And we see that the Russian military and North Korean supervisors are not interested in the survival of these Koreans at all,” he said.

Seoul’s spy agency said it received information on the capture “through real-time intelligence sharing with allies”, but did not specify any country by name.

Neither Moscow or Pyongyang have officially acknowledged the presence of North Korean troops in Russia.

US, Ukrainian and South Korean intelligence estimates however, put the number of North Korean soldiers in Russia at between 11,000 to 12,000, some of whom have already engaged in combat operations alongside tens of thousands of Russian forces to assist in recovering parts of Kursk.

Ukraine estimates more than 3000 North Korean soldiers have been killed or wounded in Kursk, while a senior US official said North Korea has seen “several hundred” casualties – both killed and wounded – in the region since October.

A South Korean lawmaker said about 100 North Korean soldiers are believed to have been killed and almost 1000 injured since being deployed to Kursk, citing the country’s intelligence agency.

Officials in Kyiv have accused Russia of trying to cover up the involvement of North Korean soldiers on the battlefield.

Earlier this month, the Ukrainian military said documents seized from three North Korean soldiers killed in Kursk were fake military identification documents with Russian names and birthplaces.

Zelensky has said Russia is attempting to conceal the losses of North Korean troops on the battlefield, resorting to extreme tactics to disguise the identity of North Korean soldiers killed in combat.

“Russians are trying… to literally burn the faces of North Korean soldiers killed in battle,” Zelensky said in a statement on X on December 17, alongside a video purportedly showing Russian soldiers setting fire to the bodies of North Korean soldiers.

“There are risks of North Korea sending additional troops and military equipment to the Russian army,” Zelensky said after receiving a report from Oleksandr Syrskyi, commander-in-chief of Ukraine’s Armed Forces.

Yesterday, Russian President Vladimir Putin sent a letter to North Korean leader Kim Jong-un in which he wrote the two countries will continue to implement the comprehensive strategic partnership treaty they signed in June, which includes a mutual defence pact, Russian and North Korean state media reported.