Diplomatic efforts to resolve a dispute over Iran's nuclear programme, which Tehran says is peaceful but the West suspects is intended to give Iran the capability to build a nuclear bomb, have been all but deadlocked for years, while Iran has continued to announce advances in the programme.
Iranian Foreign Minister Ali Akbar Salehi said a suggestion on Saturday by US Vice President Joe Biden that Washington was ready for direct talks with Iran if Tehran was serious about negotiations was a "step forward".
"We take these statements with positive consideration. I think this is a step forward but... each time we have come and negotiated it was the other side unfortunately who did not heed... its commitment," Mr Salehi said at the Munich Security Conference where Mr Biden made his offer a day earlier.
Mr Salehi also complained to Iran's English-language Press TV of "other contradictory signals", pointing to the rhetoric of "keeping all options on the table" used by US officials to indicate they are willing to use force to keep Iran from obtaining a nuclear weapon. He said: "This does not go along with this gesture [of talks], so we will have to wait a little bit longer and see if they are really faithful this time."