According to South Korea's intelligence service, two North Korean soldiers have been captured by Ukraine.

On Saturday, Ukrainian President Volodymyr Zelenskyy confirmed that two wounded North Korean soldiers who were fighting on behalf of Russia in a Russian border region were captured by Ukraine.

The Ukrainian military captured two North Korean soldiers on January 9 in the Kursk battlefield in Russia, according to Seoul's National Intelligence Service (NIS).

The two North Korean soldiers who were captured have been wounded and are being treated in Kyiv, where they are communicating with the Ukrainian security services SBU.

A video was released by SBU that purportedly shows two prisoners lying on beds within jail cells. However, the accuracy of the video could not be confirmed.

One soldier sustained a facial injury and another had an open wound and a broken leg, according to a doctor interviewed in the SBU video. Both soldiers were receiving medical care.

One soldier had no documents, while the other carried a Russian military ID card in the name of a man from Tuva.

According to Ukraine's military, North Korean soldiers are dressed in Russian military uniforms and carry fake military IDs, which could enable Moscow and its representatives at the U.N. to deny the truth.

Moscow has never publicly acknowledged the presence of North Korean forces in the Kursk border region, despite assertions by Ukraine, the U.S., and South Korea that Pyongyang has sent 10,000 to 12,000 troops to fight alongside Russia.

Ukrainian troops confirmed engagement on the ground in December, despite reports of their presence first emerging in October.

On Thursday, Zelenskyy estimated the number of killed or wounded North Koreans to be 4,000, while U.S. estimates put it at approximately 1,200.

Ukrainian soldiers, military intelligence, and experts believe that gaining first-hand experience on the battlefield will help North Korea improve as a fighting force, despite their initial inexperience and losses.

""The North Korean army is gaining real military experience for the first time in decades, posing a global challenge not only for Ukraine and Europe but the entire world, according to Yusov," said Yusov."

The Associated Press contributed to this report.