Which Soviet official told Japan’s ambassador that the Soviet Union had declared war in August 1945?

Soviet Foreign Minister Vyacheslav Molotov told Japan’s ambassador that the Soviet Union had declared war in August 1945.

Molotov delivered the notice to Japanese ambassador Naotake Satō in the Kremlin on August 8, 1945. He stated that the Soviet government would consider itself at war with Japan from August 9. The announcement followed the Soviet commitment at Yalta to enter the Pacific war after Germany’s defeat.

The Soviet declaration ended the Soviet-Japanese Neutrality Pact and opened the Soviet–Japanese War. Soviet forces invaded Japanese-held Manchuria shortly after midnight on August 9, attacking from several directions. Soviet operations also extended into southern Sakhalin and the Kuril Islands.

This event is sometimes overshadowed by the atomic bombings of Hiroshima and Nagasaki, which occurred on August 6 and August 9. The Soviet entry greatly increased pressure on Japan’s leadership because it removed hopes that Moscow might mediate a negotiated settlement with the Western Allies.