What country sent troops to north Korea during the Korean war?

During the Korean War, China sent troops to North Korea to support the North Korean forces against South Korea and United Nations troops, primarily led by the United States. The Chinese intervention began in late 1950, significantly altering the course of the war and contributing to a stalemate that lasted until the armistice in 1953. Additionally, the Soviet Union provided material and logistical support to North Korea but did not send combat troops.