Britain's Foreign Secretary William Hague said on Sunday that talks on Iran's nuclear programme could reach a deal within the next few weeks, despite the failure of negotiations in Geneva.
The inconclusive talks had "made a lot of progress", brought all sides closer together and left an agreement within reach, Hague said.
"On the question of will it happen in the next few weeks, there is a good chance of that," Hague told the BBC. "We haven't been wasting our time, but it is a formidably difficult negotiation. It is vital to keep the momentum... A deal is on the table and it can be done."
Iran and six world powers failed in marathon talks that ended late on Saturday night to clinch a deal to curb Tehran's nuclear programme.
Hague said he felt Iranian Foreign Minister Mohammad Javad Zarif wanted to reach a settlement.
"I do believe that he wants to solve this problem, that he is out to do a deal," Hague told the BBC.
Any deal would inevitably involve compromises that would not be welcomed by all countries, he added.
Asked if an agreement would contain guarantees that would satisfy the Israeli government that Iran would not be able to develop a nuclear bomb soon, Hague replied: "Will that be a deal that will please everybody? Well, no it won't because compromises will have to be made."
Israel has condemned the proposed agreement because it suspects Iran is bent on acquiring nuclear weapons. Tehran denies any such intention, saying it needs atomic power to generate electricity.