A small number of North Korean forces are already on the territory of Ukraine, CNN reported on Oct. 29, citing two Western intelligence officers.
NATO and the Pentagon previously confirmed that North Korean troops were training in Russia and that some of them were on their way to Russia's Kursk Oblast, part of which Ukrainian forces have controlled since August.
There was no confirmation of the presence of North Korean troops in Ukraine before.
"It seems that a good many of them are already in action," one of the officials told CNN, referring to the North Koreans.
The first North Korean troops were to be deployed in the combat zone on Oct. 27 or 28, President Volodymyr Zelensky said earlier.
U.S. and South Korean diplomatic and military officials will meet in Washington this week to discuss North Korea's "expanding relationship with Russia," said U.S. State Department spokesman Matthew Miller.
Presidential Office chief Andriy Yermak is also currently in Washington. According to CNN, he met with National Security Advisor Jake Sullivan and State Secretary Antony Blinken on Oct. 29. Yermak mentioned that he and Sullivan discussed "North Korean soldiers whom Russia is preparing for war."
How helpful the North Korean military will be to the Russian army on the battlefield is not yet clear. Many of the North Korean troops are special forces, and intelligence assessments suggest that Pyongyang believes its troops have greater combat power than regular Russian troops because they are better trained and specialized, officials told CNN.
The North Korean military has not been involved in a war for over 70 years, and intelligence officials believe the North Korean government sent them there largely so they could gain combat experience.
Officials also expect that at least some of the soldiers will desert their units once they are on the battlefield and that the language barrier with the Russians will be a significant obstacle to smooth operations.
The Russians are teaching North Korean soldiers basic Russian commands in training, such as "fire" and "back to your position," South Korean lawmakers told reporters on Oct. 29.
North Korea and Russia have strengthened ties since the full-scale war began, including signing a new mutual defense pact. Ukraine and Western governments have previously accused North Korea of providing weapons to Russia – allegations both Pyongyang and Moscow have denied.
Ukrainian military intelligence reported on Oct. 24 that approximately 12,000 North Korean troops, including 500 officers and three generals, were already in Russia and undergoing training at five military bases.
Three Russian soldiers will be assigned to every group of 30 North Korean fighters, Ukraine's military intelligence agency reported on Oct. 25, citing an intercepted conversation between service members of a Russian brigade in Kursk Oblast.
However, doubts remain in the Russian army about the possibility of carrying this out in practice.