Which Soviet diplomat announced the Soviet Union’s declaration of war against Japan in August 1945?

Vyacheslav Molotov announced the Soviet Union’s declaration of war against Japan in August 1945.

On August 8, 1945, Soviet Foreign Minister Vyacheslav Molotov informed Japan’s ambassador, Naotake Satō, in Moscow that the Soviet Union had declared war on Japan. The Soviet government stated that it would be at war with Japan from August 9.

Soviet forces began their invasion of Japanese-held Manchuria shortly after midnight on August 9. The campaign opened on multiple fronts and rapidly overwhelmed Japanese forces in the region. Soviet operations also expanded into southern Sakhalin and the Kuril Islands.

The declaration came after the atomic bombing of Hiroshima and before Japan’s formal surrender. It fulfilled the Soviet commitment made at Yalta to enter the war against Japan. Molotov’s announcement should not be confused with Emperor Hirohito’s later broadcast accepting the Allied surrender terms.