World powers and Iran held a third day of crunch talks on Tehran's nuclear programme on Saturday with top diplomats saying progress was being made but there was no certainty of a deal.
Adding diplomatic weight to the negotiations, Russian Foreign Minister Sergei Lavrov had arrived in Geneva, where his US, British, French and German counterparts rushed on Friday hoping to seal a breakthrough.
The hoped-for agreement seen as a first step ahead of further talks on a final deal could see Tehran freeze its nuclear efforts for as long as six months in exchange for some relief from the sanctions that have battered its economy.
Western officials, including US Secretary of State John Kerry who cut short a Middle East tour to join the talks, have expressed caution, warning major obstacles remain to be overcome.
But hopes were nonetheless high that a breakthrough first-stage agreement was in the works in the decade-old standoff.
"These negotiations have made very good progress and continue to make progress," British Foreign Secretary William Hague told journalists, adding though that it was "too early" to be sure a deal could be reached on Saturday."There is now a real concentration on these negotiations so we have to do everything we can to seize the moment and seize the opportunity to reach a deal that has eluded the world," he said.
France in particular was considered to have concerns about the deal, with its Foreign Minister Laurent Fabius saying there were "some points on which we are not satisfied". "There is an initial draft that we do not accept... I have no certainty that we can finish up" at this stage, Fabius told France Inter radio before talks started on Saturday.
In a series of meetings early today, Kerry and the European ministers met with EU diplomatic chief Catherine Ashton, who has represented the six world powers at the talks. Fabius then entered separate talks with Ashton and Iranian Foreign Minister Mohammad Javad Zarif.
Kerry, Ashton and Zarif were to hold talks later Saturday, after the three met until nearly midnight on Friday. If some sort of agreement is reached, it would be a breakthrough after a decade of negotiations between Iran and the P5+1 group comprising the United States, Britain, France, Germany, Russia and China.
Reports say the proposed deal could see Tehran stop enriching uranium to 20 percent, which is just a few technical steps from weapons grade, reduce existing stockpiles and