American film director Oliver Stone has challenged the commonly held U.S. perception that the 1945 atomic bombing of Japan ended World War II — saving a huge number of American lives in the process — as "a tremendous lie" during his visit to Hiroshima through Wednesday.

"It's easy to look at the issue simply that Americans dropped the bomb to end World War II because Japanese militarists would not give up . . . (but) that would be the surface explanation," Stone, 66, said as part of his Japan trip to attend a series of peace events commemorating the 68th anniversary of the U.S. atomic bombings of Hiroshima and Nagasaki.

"But those people who looked deeper will find out there is a much more cynical explanation," he said, noting the Soviet Union's war on Japan, begun on Aug. 9, was "a strong factor" behind Tokyo's surrender six days later.