US defence secretary Robert Gates today said he expected the international community to impose significant sanctions on Iran over its nuclear programme.
A senior US official said the United States and its allies would decide early next year whether to pursue more sanctions.
Mr Gates also told US troops in northern Iraq that military action against Iran would only delay its nuclear progress and instead urged a package of "incentives and disincentives" to convince leaders in Tehran to meet western demands.
His made his comments as European Union leaders meeting in Brussels expressed grave concern about Iran's nuclear ambitions and also warned of new sanctions.
"I think you're going to see some significant additional sanctions imposed by the international community, assuming that the Iranians don't change course and agree to do the things they signed up to do at the beginning of October," Mr Gates said.
Mr Gates was referring to a deal under which Iran would have transferred stocks of low-enriched uranium (LEU) abroad, receiving fuel in return to run a reactor producing medical isotopes.
He said Iran was "stiffing" the international community by refusing to implement what was agreed in October.
That "has brought the international community, including the Russians and the Chinese, together in a way that they have not been in terms of significant additional sanctions on the Iranians," he said.
Western powers saw the deal as reducing Iran's scope to divert LEU for potential bomb-making but Tehran later backed away from it.
The United States, Britain and France warned Iran yesterday that it may face new sanctions over its nuclear programme, but Russia and China hinted that they were not convinced more punitive steps were needed.
The exchange of views during a UN Security Council debate on Iran showed how the Western powers' desire to ratchet up the pressure on a defiant Tehran over its atomic ambitions might face tough resistance from Moscow and Beijing.
Reuters