Iran's Supreme Leader Ayatollah Ali Khamenei has welcomed comments by US President Barack Obama dampening talk of military operations against Iran over its nuclear programme, the Iranian state news agency Irna said on Thursday.

"We heard two days ago that the US president said that (they) are not thinking about war with Iran. These words are good words and an exit from delusion," Khamenei was quoted by Irna as saying.

It is rare for Iran's most powerful figure to praise the US leader. But Khamenei added that Obama had also spoken about bringing "the Iranian people to their knees through sanctions. This part of his comments shows that the illusion continues".

On Tuesday, Obama said there was a "window of opportunity" to use diplomacy to resolve issues about Iran's nuclear programme and that it was in everyone's interest to see if they can be resolved in a peaceful fashion.

The US and the European Union have imposed tough economic sanctions against the Islamic Republic over its determination to continuing enrching uranium which they believe is part of a programme to develop nuclear weapons. Iran maintains its activities are purely for energy and research needs.

The US and Israel have threatened Iran with military strikes to prevent the Shia theocracy gaining control of nuclear weapons. - Reuters