In August, the Japanese government refused surrender demands as specifically outlined in the Potsdam Declaration. With the invasion of Japan imminent, Truman approved the schedule for dropping the two available bombs. Truman always said attacking Japan with atomic bombs saved many lives on both sides; military estimates for the invasion of Japan were that it could take a year and result in 250,000 to 500,000 U.S. casualties. Hiroshima was bombed on August 6, and Nagasaki three days later, leaving 105,000 dead. The Soviet Union declared war on Japan on August 9 and invaded Manchuria. Japan agreed to surrender the following day.