North Korea will stand by Russia until its victory in Ukraine, Pyongyang's foreign minister said in Moscow on Friday, as the U.S. has warned thousands of North Korean troops could be sent to combat in the Ukraine conflict in the coming days.

North Korea's Choe Son Hui was in Moscow as the West believes up to 10,000 North Korean troops are training in Russia and on the brink of entering the more than two-year conflict on Russia's side.

U.S. intelligence has said some of the troops have made their way to the Kursk border region, with Washington and Seoul warning North Korea to withdraw its army.