How did the United States and the Soviet Union occupy different parts of Korea after Japan surrendered?

Following Japan's surrender in 1945, the United States and the Soviet Union divided the Korean Peninsula into two occupation zones along the 38th parallel.12

This division was formalized through General Order No. 1, which mandated that Japanese forces north of the 38th parallel surrender to the Soviet Union, while those south of the line surrendered to the United States. The primary motivation for this partition was to facilitate the surrender of Japanese troops, though many historians also view it as a strategic measure to prevent the Soviet Union from occupying the entire peninsula.1

In the northern zone, Soviet forces supported the establishment of a communist government led by Kim Il-Sung. In the southern zone, American forces backed the anticommunist nationalist Syngman Rhee. As Cold War tensions intensified, these separate administrative zones solidified into two distinct states by 1948, each claiming legitimacy over the entire country.324