'A more peaceful world can be ours,' Ban Ki-moon said in remarks to the Hiroshima Peace Memorial Ceremony held in Japan.

Mr. Ban, the first UN Secretary-General to take part in the ceremony, was one year old when the atomic bombs fell on Hiroshima and Nagasaki in August 1945, resulting in the deaths of more than 200,000 people.

More than 400,000 more people have died - and are continuing to die - since the end of the Second World War from the impacts of those bombs.

'Only later in life could I begin to understand the full dimension of all that happened here,' said the UN chief.

Mr. Ban has made nuclear disarmament and non-proliferation a top priority, and put forward a five-point plan in 2008 that includes recommendations on increasing security, verification, establishing a legal framework for nuclear disarmament, transparency and conventional weapons.

'Our moment has come,' he said, noting recent progress on the issue, including new leadership from the most powerful nations, new engagement in the Security Council, and new energy from civil society.

At the same time, it is vital to keep up the momentum, he said, adding that he will convene a Conference on Disarmament in New York in September, where he will push for negotiations towards nuclear disarmament.

He also highlighted the need for disarmament education in schools, including translating the testimonies of the survivors in the world's major languages, as well as teaching that 'status and prestige belong not to those who possess nuclear weapons, but to those who reject them.'

The Secretary-General arrived in Hiroshima after spending what he described as 'a profoundly moving day' in Nagasaki, where he toured the Atomic Bomb Museum and met with a number of survivors. He also laid a wreath at the monument located at ground zero, and visited a separate memorial for Korean victims.

He said his visit to Nagasaki had strengthened his conviction that nuclear weapons must be outlawed, and he urged all nations to support his five-point action plan and agree to negotiate a nuclear weapons convention at the earliest possible date.

'Together, we are on a journey from ground zero to Global Zero - a world free of weapons of mass destruction. That is the only sane path to a safer world?

'Let us realize our dream of a world free of nuclear weapons so that our children and all succeeding generations can live in freedom, security and peace,' Mr. Ban stated.