Which Allied declaration did Japan accept before signing its September 1945 surrender document?

Japan accepted the Potsdam Declaration before signing its September 1945 surrender document.

The United States, the United Kingdom, and China issued the declaration on July 26, 1945, during the Potsdam Conference. It demanded the unconditional surrender of Japan’s armed forces and warned of “prompt and utter destruction” if Japan refused.

The declaration also outlined major postwar principles. Japan’s sovereignty would be limited to the home islands and other areas determined by the Allies, its military forces would be disarmed, and war criminals would face justice. It promised that the Japanese people would not be enslaved or destroyed as a nation.

Japan’s acceptance followed the atomic bombings, the Soviet entry into the war against Japan, and internal debate over the Emperor’s position. The declaration provided the political terms that the later Instrument of Surrender formally implemented. The Cairo Declaration was an earlier Allied statement about territorial goals, not the immediate surrender ultimatum signed onto in September.