US President George W Bush has said that Iran must not be allowed to develop a nuclear weapon because it would become a threat to the world and Israel in particular.
However, he also said he was not going to prejudge what the United Nations Security Council would do if Iran was brought before it over its nuclear programme.
Mr Bush was speaking after a meeting with the German Chancellor Angela Merkel; he said the US was seeking to resolve the crisis over Iran by diplomatic means.
The British Foreign Secretary, Jack Straw, has said the UNSC may consider imposing sanctions on Iran if it fails to comply with its demands.
However, Mr Straw added that it may look at other measures first, referring to so-called Chapter Seven resolutions that do not involve sanctions.
In a BBC interview, Mr Straw said that the issue could only be resolved by peaceful means. 'No one is talking about invading Iran or taking military action against Iran,' he said.
Iran has threatened to halt UN inspections of its nuclear sites if it is referred to the UNSC.
Tehran has repeatedly denied that it is trying to manufacture nuclear weapons.
Yesterday, ministers from Britain, France and Germany responded to Iran's move to reactivate uranium enrichment research by asking for an emergency meeting of the UN's nuclear watchdog, the International Atomic Energy Agency.
The UN Secretary General, Kofi Annan, said yesterday that Iran was still keen on pursuing nuclear talks with European powers.
Mr Annan said he had spoken by phone with Iran's chief nuclear negotiator, Ali Larijani, who had made it clear that Tehran wanted a diplomatic solution.
