The United States is planning to take advantage of domestic unrest in Iran and a slowing of the country's nuclear programme to introduce tough new sanctions on Tehran.
President Barack Obama plans to focus fresh sanctions on Iran's Revolutionary Guard, the military force that oversees its pursuit of nuclear weapons. The Revolutionary Guard has also been prominent in the recent crack down on anti-government demonstrators. Mr Obama is known to be impatient having originally given Iran a deadline of the end of 2009 to make progress on complying with United Nations resolutions and suspending its uranium enrichment programme.
Tehran has not been daunted by previous sanctions but an Obama administration official said the turmoil in Iran granted "a window to impose the first sanctions that may make the Iranians think the nuclear programme isn't worth the price tag".
The administration believes that Iran's hopes of secretly enriching uranium have faltered since the disclosure in October of a secret enrichment plant under construction near Qom, the Shia Muslim holy city.
Iran suffered a second setback when nuclear inspectors reported the number of machines operating at the Natanz plant, used to enrich uranium, had dropped by 20pc since the summer.
Effective sanctions that do not have counter-productive effects would be difficult for the US to achieve. Three previous rounds of sanctions have not deterred Iran and stopping western goods would dismay Iranian demonstrators and pro-western reformists. The Revolutionary Guard, however, has extensive business interests that could be targeted.Iran cried foul at the threat of new sanctions and said the west had now given it until the end of January to accept a deal over swapping enriched uranium. It insisted that it would continue with plans to produce more enriched nuclear fuel if there was no agreement (©Daily Telegraph)