European Union Foreign Policy Chief Catherine Ashton says there is “no guarantee” her talks with Iran’s leaders could achieve a comprehensive agreement to limit or end Tehran’s nuclear ambitions, although Iranian officials expressed a little more optimistism.

“We can do it in four or five months and even shorter,” said Iranian foreign minister Mohammad Javad Zarif before he sat down to meet with Baroness Ashton for more than an hour on Sunday.  Ashton is making her first visit to Tehran as relations with the west appear to be thawing.  She was a part of the negotiating team that reached the current six-month deal to stall Iran's nuclear program in return for limited sanctions relief.

The next round of talks between Iran and the six major powers is scheduled to begin in Vienna in one week on 17 March.  Zarif cautioned that the west has got to “come to the negotiating table with a desire, decision and commitment to reach a mutually acceptable agreement” that recognizes Iran’s nuclear “rights”.

“I believe if that is the case, we can do it within the five months or four months that is left from the first phase,” he said.