Iranian foreign minister Ali Akbar Salehi said that he was "optimistic" that the United States was revamping its approach to Tehran in the protracted dispute over Iran's nuclear programme.

"I feel this new (US) administration is really this time seeking to at least divert from its previous and traditional approach vis-a-vis my country," he told a foreign policy think-tank in Berlin.

Salehi had told a security conference in the southern German city of Munich on Sunday that Iran was open to a US offer for bilateral discussions if Washington's intentions were "authentic".

And he said Iran was ready to resume talks over its disputed nuclear work with the US and five other world powers in Kazakhstan on February 25, insisting that Iran had never pulled back from the negotiations.

Iran and six world powers - the United States, China, Russia, Britain, France and Germany held three rounds of talks last year aimed at easing the standoff over Iran's nuclear activities, which Tehran insists are peaceful.