The United Nations Security Council has unanimously approved a resolution calling for nuclear disarmament. The resolution urged all countries that that have not signed the nuclear Non-Proliferation Treaty, such as Iran and North Korea, to do so.

The meeting was chaired by United States President Barack Obama. It was the first time a sitting US president has chaired a meeting of the Security Council.

Mr Obama sketched the doom scenario of a nuclear attack on a city such as New York, Moscow or Beijing. Quoting former US president Ronald Reagan, he told the meeting that "a nuclear war cannot be won and must never be fought".

On Wednesday Mr Obama made a speech to the United Nations General Assembly, in which he also argued for the ideal of a nuclear-free world.

During the speech by Iranian President Mahmoud Ahmadinejad, representatives of the United States, Canada, France and the Netherlands walked out in protest at what they described as anti-Semitic rhetoric.