Iran's violent crackdown against the protests prompted strong international criticism.

'Although Ahmadinejad has been inaugurated, clearly the Iranian people have many questions about, you know, this election and his ability to lead,' Wood said.

The US has urged Iran to return to negotiations led by the five permanent members of the UN Security Council - Britain, China, France, Russia and the US - plus Germany.

The New York Times reported earlier this week that Washington will push for fresh UN sanctions if Iran does not re-enter the discussions by the time of the UN General Assembly opens in mid-September. US officials have refused to confirm that report.