HIROSHIMA, Japan — House Speaker Nancy Pelosi yesterday became the highest-ranking sitting American official to visit ground zero of the world’s first atomic bombing.

The Democrat, who came to this western port city for a two-day annual gathering of Group of Eight legislative heads, joined other speakers in paying their respects at a memorial to the Hiroshima bombing. One by one, each bowed, then laid flowers at a white, arch-shaped monument containing the names of more than 200,000 victims of the nuclear blast.

No serving American president or vice president has ever visited Hiroshima. As speaker of the House of Representatives, Ms. Pelosi is second in line to the presidency after Vice President Cheney.

President Carter stopped by the memorial in 1984, after his term, as a private citizen.

The leader of Japan’s House of Representatives, Yohei Kono, said no decisions were made during the meeting on peace and disarmament, but he emphasized the symbolic importance of discussing the future of nuclear weapons in the city.

“The fact that they all came to Hiroshima has significant meaning,” Mr. Kono said after the group’s daylong meeting yesterday.

“I hope that even more international political leaders come to Hiroshima and Nagasaki and see with their own eyes, so that they will be able to strengthen their resolve for disarmament and nuclear disarmament going forward.”

Ms. Pelosi said nothing to reporters after the ceremony, a possible reflection of the lingering sensitivity that surrounds the history of Hiroshima.