John Kerry visits Hiroshima memorial 7 decades after atomic bomb; delivers message of peace and hope

US Secretary of State John Kerry visited the revered memorial to Hiroshima's atomic bombing on Monday, delivering a message of peace and hope for a nuclear-free world seven decades after the US used the weapon for the first time in history and killed 140,000 Japanese.

Kerry became the most senior American official to travel to city, touring its peace museum with other foreign ministers of the Group of Seven industrialised nations and laying a wreath at the adjoining park's stone-arched monument, the exposed steel beams of Hiroshima's iconic A-Bomb Dome in the distance.

The otherwise somber occasion was lifted by the presence of about 800 Japanese waving flags of the G7 nations, including that of the US.

Kerry didn't speak publicly at the ceremony, though could be seen with his arm around Japanese Foreign Minister Fumio Kishida, a Hiroshima native, and whispering in his ear. The ministers departed with origami cranes in their respective national colours around their neck, Kerry draped in red, white and blue.

Kerry writes in the museum's guest book.

"Everyone in the world should see and feel the power of this memorial," Kerry wrote in the museum's guest book. "It is a stark, harsh, compelling reminder not only of our obligation to end the threat of nuclear weapons, but to rededicate all our effort to avoid war itself."

"War must be the last resort never the first choice," he added. "This memorial compels us all to redouble our efforts to change the world, to find peace and build the future so yearned for by citizens everywhere."

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

No serving president visited the site

No serving US president has visited the site, and it took 65 years for a US ambassador to attend Hiroshima's annual memorial service.

Many Americans believe the dropping of atomic bombs here on August 6, 1945, and on the Japanese city of Nagasaki three days later were justified and hastened the end of the war.

Nevertheless, Japanese survivors' groups have campaigned for decades to bring leaders from the US and other nuclear powers to see Hiroshima's scars as part of a grassroots movement to abolish nuclear weapons.

As Kerry expressed interest, neither Japanese government officials nor survivor groups pressed for the US to say sorry.

And a senior American official travelling with Kerry said no apology would occur.

Shortly before the ceremony, Kerry called it "a moment that I hope will underscore to the world the importance of peace and the importance of strong allies working together to make the world safer and, ultimately, we hope to be able to rid the world of weapons of mass destruction."