Two western intelligence officials reportedly said a small number of North Korean troops are already inside Ukraine.

According to CNN on Tuesday, the intelligence officials expect that number to grow as the North Koreans complete training in eastern Russia and move toward the front lines of the war.

One of the officials reportedly said “a good many of them” appear to be in action already. 

Earlier on Tuesday, South Korea’s National Intelligence Service(NIS) said some North Korean troops, including high-ranking military officers, may have moved to the front lines. 

In response to the Ukrainian military’s claim that about three-thousand North Korean soldiers are training in the Kursk region, the NIS acknowledged that it’s possible but added that it can’t say for sure yet. 

On Monday, the U.S. departments of State and Defense said North Korea has sent about ten-thousand troops to Russia for training, and that some have moved closer to Ukraine.