Which Soviet foreign minister informed Japan’s ambassador that the USSR had declared war in August 1945?

Vyacheslav Molotov informed Japan’s ambassador that the USSR had declared war in August 1945.

On August 8, 1945, Soviet Foreign Minister Vyacheslav Molotov summoned Japanese ambassador Naotake Satō in Moscow and announced that the Soviet Union would consider itself at war with Japan from August 9. Soviet forces then launched their offensive against Japanese positions in Manchuria.

The declaration fulfilled the Soviet commitment made at the Yalta Conference to enter the war against Japan after Germany’s defeat. It also ended the Soviet-Japanese Neutrality Pact before its stated expiration, although Moscow had already notified Japan in April that it would not renew the agreement.

The Soviet entry coincided with the final atomic-bombing campaign and intensified pressure on Japan’s leaders. It is often discussed alongside the bombings as one of the major shocks leading to surrender.