While publicly stating their intent to fight on to the bitter end, Japan's leaders (the Supreme Council for the Direction of the War, also known as the 'Big Six') were privately making entreaties to the publicly neutral Soviet Union to mediate peace on terms more favorable to the Japanese. Together with Great Britain and China, the United States called for the unconditional surrender of the Japanese armed forces in the Potsdam Declaration on July 26, 1945-the alternative being 'prompt and utter destruction'. By the end of July 1945, the Imperial Japanese Navy (IJN) had become incapable of conducting major operations and an Allied invasion of Japan was imminent. The surrender of Imperial Japan was announced by Japanese Emperor Hirohito on August 15 and formally signed on September 2, 1945, bringing the hostilities of World War II to a close.
