UN Forces advance to the Chinese border, Korea.

By 1 October 1950, General MacArthur's UN Command (UNC) forces had pushed the North Korean People's Army (KPA) back over the 38th parallel with the South Korean army (ROK) in pursuit. MacArthur had publically demanded the KPA's unconditional surrender and on 7 October, the UNC followed the ROK's forces northwards.

The UNC's X Corps landed at Wonsan in the southeast of North Korea and at Riwon (already occupied by ROK forces) in the northeast. The Eighth U.S. Army and the ROK Army advanced along western Korea and occupied the North's capital city, Pyongyang, on 19 October 1950. The 187th Airborne Regimental Combat Team, in an airborne operation, captured Sunchon and Sukcho on 20 October 1950, in order to cut the road to China and prevent North Korea's leaders from escaping - and rescue prisoners of war. By the end of October 1950, the UNC forces had captured 135,000 KPA prisoners of war.

As they approached the Chinese border, the UNC was split east to west by some 50 to 100 miles of mainly mountainous terrain. Despite this divided force, General MacArthur believed that the UNC should cross the Yalu River and destroy Chinese support for the KPA, but President Truman countered his haste by ordering caution.