U.S. President Joe Biden vowed to strive toward a world free of nuclear weapons in a message he left on a visit to a Hiroshima museum documenting the devastation caused by a U.S. atomic bomb in 1945, the Japanese government said Saturday.

"May the stories of this Museum remind us all of our obligations to build a future of peace," Biden wrote in the guest book of the Hiroshima Peace Memorial Museum, which he visited with other Group of Seven leaders at the start of the three-day summit in western Japan on Friday.

"Together let us continue to make progress toward the day when we can finally and forever rid the world of nuclear weapons. Keep the faith!" he added.

U.S. President Joe Biden signs a guestbook at the Hiroshima Peace Memorial Museum in Hiroshima on May 19, 2023, on the first day of the three-day Group of Seven summit in the western Japan city. (Kyodo)

Biden is the second U.S. sitting president after Barack Obama to set foot in Hiroshima, the site of the world's first nuclear attack. He and the other G-7 leaders, including from fellow nuclear powers Britain and France, made an unprecedented joint visit to the museum.

The facility displays belongings left behind by victims, photos, and other materials that convey the horror of the dropping of the U.S. atomic bomb on Hiroshima on Aug. 6, 1945. The attack is estimated to have killed 140,000 people by the end of 1945.

A second atomic bomb was dropped on Nagasaki, southwestern Japan, on Aug. 9, and Japan surrendered six days later, prompting the end of World War II.

When Obama stopped by Hiroshima in 2016, a trip made on the occasion of the previous G-7 summit in Japan, he delivered a speech and met with representatives of atomic bomb survivors at the city's Peace Memorial Park, while also briefly visiting the museum.

 U.S. President Barack Obama (R) puts his hand on the shoulder of Japanese Prime Minister Shinzo Abe at the Peace Memorial Park in Hiroshima on May 27, 2016. The Atomic Bomb Dome can be seen in the background. Obama became the first sitting U.S. president to visit the atomic-bombed city that day. (Kyodo)==Kyodo

The details of the G-7 leaders' joint visit to the museum have not been disclosed by the Japanese government, except for their holding exchanges with an atomic bomb survivor. The reticence possibly takes heed of widespread views in the United States that the two atomic bombs dropped on Japan were necessary to end World War II quickly.

A diplomatic source said Friday that the G-7 leaders saw some of the museum's permanent exhibits, which included photos capturing the scale of destruction in the city.

Biden did not make any statement at the park after leaving the museum. He took part with other G-7 leaders in a wreath-laying ceremony at a cenotaph for the atomic bomb victims at the park.

(From L) Japanese Prime Minister Fumio Kishida, U.S. first lady Jill Biden, U.S. President Joe Biden and Kishida's wife Yuko walking toward Hiroshima Peace Memorial Museum in the Peace Memorial Park in Hiroshima on May 19, 2023, ahead of the start of the three-day Group of Seven summit in the western Japan city. (Kyodo) ==Kyodo

His National Security Adviser Jake Sullivan said earlier that Biden has no plans to issue an apology on behalf of the United States for the use of an atomic bomb on Hiroshima during his trip to the city.

First Lady Jill Biden, meanwhile, wrote in the museum's guest book, "On the occasion of the G7, as we gather to continue building a world that is peaceful and free, this museum reminds us of our purpose. Thank you for your warm welcome."

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