HIROSHIMA, Japan (AP) — Secretary of State John Kerry is delivering a message of peace and hope for a nuclear-free world during his trip to Japan .

On Monday, Kerry became the most senior American official ever to visit the revered memorial to Hiroshima's atomic bombing seven decades ago.

He toured the city's Peace Memorial Park and Museum with other foreign ministers of the Group of Seven industrialized nations. Some 140,000 Japanese died when the United States dropped the bomb in the final days of World War II.

Kerry's appearance just footsteps away from Ground Zero further marks an evolution for the United States, whose leaders avoided the city for many years because of political sensitivities.

No serving U.S. president has visited the site, and it took 65 years for a U.S. ambassador to attend the city's annual memorial service. Many Americans believe the dropping of the atomic bombs on Hiroshima on Aug. 6, 1945, and the Japanese city of Nagasaki three days later were justified and hastened the end of the war.