The United Nations' nuclear watchdog, the International Atomic Energy Agency, has expressed deep and increasing concern about Iran's nuclear programme.
A resolution, passed by the agency's board, called on Tehran to clear up outstanding questions about its nuclear capabilities without delay.
Last week, an IAEA report said there was considerable evidence that Iran had been undertaking experiments geared towards developing nuclear weapons capability.
The White House welcomed a resolution and vowed to keep up pressure on Tehran to abandon its nuclear drive.
“The resolution by the International Atomic Energy Agency expressing growing concern about Iran's atomic work had exposed "the hollowness of Iran's claims" that its nuclear program was for purely civilian purposes, White House Press Secretary Jay Carney said in a statement.
"The whole world now knows that Iran not only sought to hide its uranium enrichment program from the world for more than two decades, but also engaged in covert research and development related to activities that can have only one application: building a nuclear warhead," he said.
The resolution won overwhelming support at a meeting of the IAEA, but did not mention concrete punitive steps, reflecting Russian and Chinese opposition to backing Iran into a corner.
Washington already has orchestrated tough sanctions against Iran at the UN.
EU Foreign Policy Chief Catherine Ashton today urged Iran Friday to accept an offer of talks on its nuclear programme.
"I urge Iran once again to respond positively to the offers and proposals made by myself, together with the E3+3," said Ms Ashton, who is also the negotiator for the group of six which comprises EU powers Britain, France, Germany plus China, Russia and the US.
