The US president said he wanted peaceful persuasion to prevail.

"It's very important for the Iranians to understand there is a common desire by a lot of nations in this world to convince them - peacefully convince them - that they ought to give up their weapons ambitions," George Bush said, adding that he would keep consulting allies on the issue.

Britain said it would ask the Security Council to increase pressure on Iran after the report by Mohamed ElBaradei, chief of the International Atomic Energy Agency (IAEA).

Philippe Douste-Blazy, the French foreign minister, said the council should decide the next step, insisting on a peaceful way out of a "worrying situation for the international community".

The council could eventually impose sanctions on Iran, which has vowed to go on enriching uranium, whatever the consequences.

Jack Straw, the British foreign secretary, said the Security Council should now send a stronger signal to Tehran.

Divided council

The United States, backed by Britain and France, favours limited sanctions if Iran refuses to shelve enrichment quickly.

"There are a lot of problems in the region and we should not do anything that would cause the situation to become even more complicated"

Wang Guangya,
China's ambassador to the UN

Russia and China, the Security Council's other two veto-holding permanent members, have so far opposed such moves.

John Bolton, the US ambassador to the United Nations, said the report made clear Iran had not complied with UN demands and said Washington would seek council approval of a resolution making those demands mandatory under international law.

Wang Guangya, China's UN ambassador, said almost all council members wanted a diplomatic solution to the Iran crisis.

"There are a lot of problems in the region and we should not do anything that would cause the situation to become even more complicated," he said when asked if Beijing would now back sanctions on Iran based on the findings of the IAEA report.

Chinese and US diplomats said the United States was trying to arrange a meeting of foreign ministers of the five permanent council members and Germany in New York on May 9.