North Korea's deployment to Russia to aid its war against Ukraine has the potential to lengthen the already 2½-year-old conflict and draw in others, U.S. Defense Secretary Lloyd Austin said Wednesday.

Some 10,000 North Korean forces have already been deployed to eastern Russia, wearing Russian uniforms and carrying Russian equipment, Austin noted, in what he said looked increasingly like a deployment to support Russia's combat operations in the Kursk region, near the border with Ukraine.

Ukrainian forces staged a major incursion into Kursk in August and hold hundreds of square kilometers of territory there.