South Korea's spy agency says an estimated 4,700 North Korean soldiers have been killed or wounded while fighting alongside Russia against Ukrainian forces.

FILE - In this June 15, 2020, file photo, South Korean army soldiers patrol along the barbed-wire fence in Paju, South Korea, near the border with North Korea. A North Korean diplomat who served as the country's acting ambassador to Kuwait has defected to South Korea, according to South Korean lawmakers who were briefed by Seoul's spy agency on Tuesday, Jan. 26, 2021. (AP Photo/Ahn Young-joon, File)SEOUL – A North Korean diplomat who served as the country’s acting ambassador to Kuwait has defected to South Korea, according to South Korean lawmakers who were briefed by Seoul’s spy agency. In September 2017, the Kuwaiti government expelled North Korea's ambassador and four other diplomats following North Korean nuclear and missile tests. More than 33,000 North Koreans have defected to South Korea since the end of the 1950-53 Korean War, according to South Korean government records.