North Korean soldiers are considered to be highly disciplined and well-trained, but their lack of combat experiences and unfamiliarity with the largely flat plains that make up most battlefields in the Russian-Ukraine war have made them easy targets for drone and artillery strikes.

South Korea’s spy agency said last week that it assessed about 300 North Korean soldiers had died and another 2,700 had been injured. Earlier in January, Ukrainian President Volodymyr Zelenskyy put the number of killed or wounded North Koreans at 4,000, though U.S. estimates were lower at around 1,200.