However, the statement warned that should Iran continue its "troubling" behaviour, the US would step up efforts to further isolate Iran economically and politically.
 
Western powers have accused Iran of seeking to obtain nuclear weapons but Iran insists its nuclear programme is solely for peaceful energy purposes.

Under George Bush, the former US president, Washington refused to engage in direct negotiations with Iran unless it first stopped enriching uranium, and also led efforts to push for increased economic sanctions against Iran.

Hillary Clinton, the new US secretary of state, faced criticism from Iran after she said during her failed campaign to be president that the US would "totally obliterate" Iran if it attacked Israel.