This footage posted on X by the Center for Strategic Communication and Information Security of Ukraine shows North Korean soldiers apparently receiving Russian gear, Oct. 18. Yonhap

North Korean troops were engaged in combat in Russia's Kursk in recent days for the first time, two U.S. officials told Reuters on Wednesday.

One of the officials, speaking on the condition of anonymity, said they took part in combat on Nov. 4. The officials did not say whether there were any North Korean casualties and did not provide further details on the engagement.

President Volodymyr Zelenskyy said on Tuesday that the first battles between the Ukrainian military and North Korean troops "open a new page in instability in the world" after his defence minister said a "small engagement" had taken place.

Ukrainian Defense Minister Rustem Umerov confirmed, in an interview with South Korean television, that the first engagement had occurred with North Korean troops, an apparent escalation in a conflict that began when Russia invaded Ukraine in 2022.

Earlier this week the Pentagon said that there were at least 10,000 North Korean troops in Kursk, adding that between 11,000 and 12,000 troops were in Russia all together. (Reuters)