Which declaration did Japan accept before Emperor Hirohito announced surrender in 1945?

Japan accepted the Potsdam Declaration before Emperor Hirohito announced surrender in 1945.

The declaration was issued at Potsdam 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 declaration after entering the war against Japan.

Hirohito's August 15 broadcast told the Japanese people that the government had accepted the terms of this “joint declaration.” The address used formal language and did not plainly explain every condition, but its meaning was that Japan would cease fighting.

The Potsdam Declaration was not itself the final surrender document. Its terms provided the political basis for surrender, while the Instrument of Surrender signed aboard USS Missouri on September 2 made the capitulation formal and documented.