France's foreign minister, Laurent Fabius, on Thursday left the nuclear talks taking place with Iran in Vienna.
However, he said he would return Sunday evening in the hope that sufficient progress had been made over the next few days to reach a final deal, Reuters reported.
"There has been some progress, but we are not at the end of the negotiations," Fabius said after meeting his counterparts before leaving for Paris.
"I have decided to return to Vienna on Sunday evening. I hope that at that stage we will be in a situation to move, perhaps, and I hope so, to find a definitive solution that will enable a robust agreement," he was quoted as having said.
Iran and the six major powers had originally set a deadline of June 30 to reach a final deal, but when they failed to meet that deadline, they agreed to extend the deadline to July 7.
Just last week, Fabius outlined France's three key conditions for signing a deal – none of which Iran has met so far.
"What we want is a robust deal that recognizes Iran's right to civil nuclear power, but guarantees that Iran gives up definitively the nuclear weapon," he said at the time.
"For this there are three indispensable conditions: a lasting limitation of Iran's research and development capacity, a rigorous inspection of sites, including military if needed, and the third condition is the automatic return of sanctions in case it violates its commitments," he added.
Fabius has several times made clear that France will not agree to a deal if Iran so long as it rules out inspections of its military sites as part of the final agreement.
He previously said Iran wants 24 days’ notice before international inspectors could visit its nuclear sites, and warned against that move, saying "a lot of things can disappear" in 24 days.