Which 1945 declaration's terms did Japan agree to accept when it announced its surrender?

Japan agreed to accept the terms of the Potsdam Declaration when it announced its surrender.

The Potsdam Declaration was issued on July 26, 1945, by the United States, the United Kingdom, and China. It demanded Japan's unconditional surrender and warned of “prompt and utter destruction” if Japan refused. The Soviet Union joined the war against Japan later, on August 8, after initially not signing the declaration.

The declaration outlined major Allied goals, including the elimination of militarism, limitation of Japanese sovereignty to specified home islands, disarmament of Japanese forces, and the establishment of a peaceful government reflecting the freely expressed will of the Japanese people.

Japan's government communicated its acceptance in August 1945, with Hirohito's radio address making the decision public on August 15. The formal Instrument of Surrender, signed on September 2, stated that Japan accepted the provisions of the Potsdam Declaration.

The Potsdam Declaration is distinct from the Cairo Declaration, which had been issued in 1943 and focused on Allied objectives concerning Japan's territorial expansion.