The Japanese city of Hiroshima is marking Friday the 65th anniversary of the world's first atomic bomb attack in the presence of representatives from 74 nations, BBC reports.

The officials are gathered in Hiroshima to mark the moment the bomb was dropped, killing 140 000 people instantly or within months of the bombing in 1945, in the final days of World War II. Japan surrendered after a second atomic bomb was dropped on Nagasaki three days later, on August 9.

This year’s commemoration is marked by the first ever attendance of a representative of the United States, whose military aircraft delivered the bomb attack.

The ceremony took place at the site where the bomb was dropped 65 years ago, and included school choir performances, solemn ringing of bells and a minute of silence at the exact time the bomb fell. Symbolic offerings of water were made to the 140 000 victims, as many died of thirst in the days and weeks after the attack.

UN Secretary General Ban Ki-moon, who also attended the ceremony for the first time, presented flowers at the Eternal Flame in Hiroshima's Peace Memorial Park. He told the crowd of 55 000 people that the time had come to move from "Ground Zero, to Global Zero" - a world without any nuclear weapons.

Japan is known as a strong supporter of the abolition of nuclear weapons.

Hiroshima's mayor welcomed Washington's decision to send US Ambassador John Roos to the event while the latter stated his presence is a chance to show resolve towards nuclear disarmament, which US President Barack Obama has said is a top objective.

The appearance of an US official at the ceremony is being seen by some political experts as a sign that Obama may visit Hiroshima when he comes to Japan, which will be a first for a sitting US president. It is not, however, expected that he will offer apologies for the bombing as some in Japan demand.