On 26 July 1945, the Allies called for the unconditional surrender of Japan in the Potsdam Declaration. The Japanese authorities, realising they would probably lose the war, began to make firm plans for Indonesian independence, more to spite the Dutch than anything else. On 6 August, an atomic bomb was dropped on Hiroshima. On 7 August, the "Nanpo Gun" headquarters announced that an Indonesian leader could enact a body called the Preparatory Committee for Indonesian Independence (PPKI). The dropping of a second atomic bomb on Nagasaki, and the Soviet invasion of Manchuria on 9 August prompted the Japanese to surrender unconditionally on 15 August 1945. Sukarno and Hatta declared independence on 17 August 1945, and the PPKI met the following day.