South Korea's top envoy to the United Nations said Thursday that North Korean troops are being dissipated as "expendables" in Russia's war against Ukraine and treated as a "cynical" means of sustaining the North Korean regime.

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.

Ukrainian President Volodymyr Zelensky said 3,800 North Korean soldiers had been killed or injured in Kursk in an interview in early January.

Over 12,000 North Korean troops are estimated to be fighting against Ukrainian forces in Russia’s Kursk region, the United Nations Security Council learned last week.