Iran's Salehi says believes US changing approach to Tehran

"As I have said yesterday, I am optimistic, I feel this new administration is really seeking this time to at least divert from its previous traditional approach vis a vis my country," he told the German Council on Foreign Relations in Berlin.

Tehran insists its nuclear program is peaceful but the West suspects it is intended to give Iran the capability to build a nuclear bomb.

Salehi, who attended the Munich Security Conference at the weekend where Biden made the offer, said in Berlin that it was still very difficult for Tehran and Washington to trust each other. "How do we trust again this new gesture?" he said.

Negotiations between Iran and six major world powers - Russia, China, the United States, Britain, France and Germany - over Tehran's nuclear activities have been deadlocked since a meeting last June.

European Union officials have accused Iran of dragging its feet in weeks of haggling over the date and venue for new talks.

(Reporting by Stephen Brown; Editing by Gareth Jones and Pravin Char)