Secretary of State John Kerry became the first US official of his rank to visit Hiroshima, the Japanese city that became the victim of the first atomic bombing by the US that killed more than a million people. Kerry was accompanied by other G7 foreign ministers, who were in Japan for a meeting. Hiroshima-born Japanese Foreign Minister Fumio Kishida led Kerry and his counterparts on a 45-minute tour of the nuclear attack site.

The foreign ministers visited a museum built in memory of the victims of the 1945 bombing. The museum has documents, photographs and descriptions of the harrowing experiences of the bombing victims. Many were killed instantly in the attack, while many others succumbed to the fatal consequences of exposure to nuclear radiation many years after the attack. Three days after the Hiroshima attack, the US dropped another atomic bomb on Nagasaki in Japan.

Kerry was not expected to issue an apology to Japan for the US attacks. He, however, expressed grief over the loss of lives. Stressing the need to build a peaceful world, Kerry wrote in the museum guestbook that it was "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," Kerry's message reads, according to the Wall Street Journal.

Following the museum visit, the G7 foreign ministers laid a wreath at the 30-acre memorial park, where they were greeted by about 800 Japanese schoolchildren. They also visited the A-Bomb Dome, over which the atomic bomb had exploded. The dome, also called the Gembaku Dome, is located across the river from the museum and is part of the memorial park.

Kerry's visit to the atomic bombing site is seen as a precursor to President Barack Obama's visit to the city. Although no confirmation has come from the White House, speculation is rife that Obama could visit Hiroshima during his upcoming Japan visit in May for the G7 summit.