North Korea is gaining crucial military experience and equipment by sending troops to Russia, a U.S. official warned the United Nations, making the regime a growing threat to neighboring countries.

Russia has endured over 700,000 casualties since launching its full-scale invasion of Ukraine in 2022—more than in all of Moscow’s conflicts since World War II combined, U.S. Defense Secretary Lloyd Austin said on Jan.

North Korea is “significantly benefiting” from its troops gaining battlefield experience fighting alongside Russian forces as it makes them more capable of waging war against rivals South Korea and Japan,