HIROSHIMA, Japan — Secretary of State John F. Kerry paid an emotional visit Monday to a museum and marker near ground zero in the city where the United States dropped an atomic bomb in the waning days of World War II.

Kerry and his fellow foreign ministers from six other powerful democracies first toured the Hiroshima Peace Memorial museum, where exhibits display the aftermath of the bomb nicknamed “Little Boy” – from charred tricycles and melted roof tiles to cancerous tongues and models of people with melting skin.

Then they walked solemnly to lay wreaths of white and pink carnations at a cenotaph that frames an eternal flame and the skeletal ruins of the one, dome-shaped building left standing. They approached the marker past about 800 elementary schoolchildren from neighborhood schools who cheered and waved the national flags of the visiting diplomats, in a calculated effort to keep the focus on the future and efforts to rid the world of nuclear weapons.

The presence of laughing children seemed to lift the spirit of the diplomats, minutes after they had spent almost an hour touring the museum’s gruesome and poignant exhibits. One minute, they were standing grim-faced at the cenotaph, laying wreaths with their names and the countries they represented. The next, they smiled and bent over to shake hands or hug the young children who approached them with paper leis. As they talked to the children, their backs to the marker, a brisk wind arose and blew several wreaths off their silver mounts, but they were quickly put back into place and secured.

The diplomatic line-up at the wreath-laying ceremony presented a strong image of nations once locked in war with each other and now standing shoulder to shoulder as allies. Kerry stood between Japanese Foreign Minister Fumio Kishida and British Foreign Secretary Philip Hammond. They were joined by foreign ministers from Germany, Italy, France and Canada, as well as the European Union.

In an indication of the emotional power the site packs, the diplomats spontaneously decided to delay their departure and walk past the so-called atomic bomb dome building that was an industrial promotional hall just across the river from Peace Park.

“Everyone in the world should see and feel the power of this memorial,” Kerry wrote in a guest book after touring the museum. “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. 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 words seemed to be an oblique reference to a possible visit by President Barack Obama, who comes to Japan next month to meet with the leaders of the G-7 states. No decision has been made whether he will come to Hiroshima.

Kerry’s visit is considered a test run for a potential Obama visit. Most Japanese say they do not expect an apology for the two bombs at Hiroshima and Nagasaki, which together killed about 225,000 people on the days they exploded and in the immediate aftermath. In all, an estimated 350,000 died within five years.

Kerry and other State Department officials tread delicately around his visit. They took care to straddle the ground between an empathetic acknowledgment of the bomb’s massive death toll, and a focus on the quest for a nuclear-free future and a bilateral relationship that has transcended enmity to become an alliance.

“While we will revisit the past and honor those who perished, this trip is not about the past,” Kerry said before a meeting with the Japanese foreign minister. “It’s about the present and the future particularly, and the strength of the relationship that we have built, the friendship that we share, the strength of our alliance, and the strong reminder of the imperative we all have to work for peace for peoples everywhere.”

The visit to the Hiroshima museum and the surrounding Peace Park was the emotional centerpiece of Kerry’s two-day visit to attend a meeting of foreign ministers from the Group of 7 countries, who have discussed the war in Syria and the resulting refugee crisis in Europe.

More than seven decades after the United States became the only nation to ever deploy nuclear bombs, the decision to pay a visit to Hiroshima remains controversial. Nancy Pelosi, then the House Speaker, was the highest ranking representative of the U.S. government to visit the historical site. Several under secretaries of state have paid visits. Jimmy Carter came as a past president and Caroline Kennedy, the U.S. ambassador to Japan, has come more than once.

Daryl Kimball, executive director of the D.C.-based Arms Control Association, said the foreign ministers’ visit to the peace memorial was “appropriate and overdue.” He encouraged Obama to make a speech at either Hiroshima or Nagasaki, where the United States dropped an atomic bomb three days after Hiroshima, and make the case for nuclear non-proliferation.

“It would provide an historic and timely opportunity to underscore why it is in every country’s interest take further concrete steps to prevent the use of nuclear weapons, and to explain why a nuclear exchange involving any of the world’s nuclear-armed states would result in catastrophic human, social, environmental, and economic consequences,” he wrote in an email.

Few Japanese are said to seek an apology for the decision to drop atomic bombs on the two densely populated cities, which many veterans believe hastened the end of the war.

But Michiko Yamaoka is not among them. The 65-year-old daughter of two survivors comes to the museum once a week to tell her parents’ story, which she said hastened her father’s death from leukemia and led to a lifetime of health woes for her mother, now 91.

She said she wants to hear some acknowledgment from the U.S. government’s leaders saying, “We remember that horrible day, even today.”

State Department officials said they were comfortable about the decision to hold the Group of 7’s ministerial meeting at Hiroshima, and have heard no suggestions from Japanese officials that an apology would be appropriate.

“There is no effort on the part of the people – the government of Hiroshima, the Government of Japan – to seek an apology from the United States, nor is there any interest in reopening the question of blame for the sequence of events that culminated in the use of the atomic bomb,” said a senior State Department official, speaking on the eve of Kerry’s visit, anonymously under State Department rules for briefing reporters.

“The good news here is that both governments and both people are firmly focused on what’s important, and what’s important is the future, and what’s important is how we can work together to secure that future.”

The official said Kerry’s visit was not meant as an endorsement of all the views represented at the museum. Some exhibits offer an alternative history that differs from what most Americans learn about the bomb. One exhibit says Japan was on the verge of surrendering, but the United States dropped the bomb to justify the cost of the Manhattan Project.

Kerry’s presence was “in no way, shape or form an endorsement of every caption or every label to an exhibit within the museum,” the State Department official said. Rather, he said, it was a show of respect to the Japanese foreign minister, who is a Hiroshima native, and the city’s inhabitants.

“I think and I hope that his visit will show that the reconciliation between the U.S. and Japan has advanced to an extraordinary level,” the official said. “That the American people and the Japanese people share a revulsion towards war and a determination to work for peace. That he admires, as I think most of us do, the resilience and the determination of the people of Hiroshima, who have rebuilt with love in their hearts, not hatred.”

Following their visit to the museum and memorial site, the diplomats issued four highly detailed, joint communiques and declarations laying out their positions on a wide range of issues and conflicts around the world. They called for nuclear disarmament, and beseeched North Korea to abandon its pursuit of nuclear weapons. They decried the efforts of terrorist groups to attain weapons of mass destruction, both chemical and nuclear.

They addressed the symbolism of meeting in Hiroshima 71 years after the end of World War II, which they said had “unleashed unprecedented horror upon the world.”

“The people of Hiroshima and Nagasaki experienced immense devastation and human suffering as a consequence of the atomic bombings and have rebuilt their cities so impressively,” one declaration stated.

“In this historic meeting, we reaffirm our commitment to seeking a safer world for all and to creating the conditions for a world without nuclear weapons in a way that promotes international stability. This task is made more complex by the deteriorating security environment in a number of regions, such as Syria and Ukraine, and, in particular by North Korea’s repeated provocations.”