Washington lobbies for UN censure of Iran's nuclear plans

America is pushing for United Nations action against Tehran over its concerns that Iran may be running a nuclear weapons programme.

Washington was seeking a declaration from the board of the International Atomic Energy Agency (IAEA) saying that Iran had violated the nuclear non-proliferation treaty to which it was a signatory, diplomats said yesterday.

The United States has accused Iran of secretly embarking on a programme to enrich uranium at Natanz, in southern Iran, which it fears could be used to make nuclear weapons.

The diplomats said America had requested support from Russia, France, Britain, Germany and other members of a board of 35 countries – the main decision-maker at the UN nuclear watchdog agency – before its meeting next month.

Britain indicated yesterday that it was receptive to the US overtures. A spokeswoman for the Foreign Office said: "We share US concerns about the scale and scope of the Iranian nuclear programme. We'll be listening carefully to the [IAEA] director general's report at the next board meeting. We will consider next steps in the light of that report."

In Washington, George Bush said: "I've always expressed my concerns that the Iranians may be developing a nuclear programme. I have done so publicly, I have done so privately. I expressed those concerns to [President] Vladimir Putin when I was in Russia." The IAEA will publish its report next month. "We'll wait and see what it says," Mr Bush said.

A declaration from the board could restrict itself to expressing concern about a possible violation or it could increase pressure on Tehran to account for its activities by referring the issue to the Security Council. The latter would strain American-Iranian relations, whichdeteriorated last year when Mr Bush included Iran in his "axis of evil" of countries supporting terrorism.

The diplomats, who spoke on condition of anonymity, said Mohamed al-Baradei, the director general of the IAEA, which is based in Vienna, was taken aback at what he saw on a visit to the facility at Natanz in February. "It's a sophisticated uranium-enrichment plant, and they had come a long way," one said. "He was struck by the sophistication and the advanced stage of the project."

Agency officials were unable to comment yet on whether Tehran had violated its commitments to the treaty.

Whether Moscow would back tough action is unclear. America claims that expertise from Russia, which has built a £500m nuclear power plant in Bushehr, southern Iran, could be used to make weapons. Iranian officials say their nuclear programme is for electricity, not defence.