WASHINGTON – The United States is “concerned” about reports of North Korean soldiers fighting for Russia in Ukraine, a White House spokesman said Tuesday.

Ukrainian President Volodymyr Zelensky this week accused North Korea of ​​transferring personnel to Russian forces and said its intelligence services had informed him of “North Korea's actual involvement in the war” in Ukraine.

The Kremlin dismissed the accusation as “fake news”.

White House National Security Council spokesman Sean Savett said that the involvement of North Korean troops in Ukraine, if true, would represent a significant expansion of defense ties between North Korea and Russia.

“Such a move would also represent a new level of desperation for Russia as it continues to suffer significant battlefield losses in its brutal war against Ukraine,” Savett said in a statement.

Washington says North Korea has supplied Russia with ballistic missiles and ammunition. Moscow and Pyongyang denied arms transfers but promised to strengthen military ties, possibly through joint exercises.

U.S. Army Indo-Pacific commander Gen. Charles Flynn said at an event in Washington that North Korean personnel involved in the conflict would allow Pyongyang to receive real-time feedback on its weapons, something not possible in the past had been.

“This is different because they provide capabilities and – open source reporting – there is also a workforce there,” he said at the Center for a New American Security.

“This kind of feedback from a real battlefield to North Korea to be able to make adjustments to its weapons, its ammunition, its capabilities and even its population — is very concerning to me,” he said.

Russian President Vladimir Putin signed a deal with North Korean leader Kim Jong Un during his visit to Pyongyang in June, saying it included a mutual assistance clause in which each side agreed to help the other ward off external aggression.