Paris, France (CNN)Negotiations over the revival of a 2015 deal that would see Iran curb uranium enrichment in exchange for sanctions relief will conclude in days, French Foreign Minister Jean-Yves Le Drian told the country's lawmakers on Wednesday.
Decision on Iran nuclear deal 'days away,' says French foreign minister
"We are coming ... to the hour of truth," Le Drian said of ongoing negotiations in Vienna to salvage the landmark deal -- which former President Donald Trump abandoned in 2018, and Tehran began to withdraw from a year later.
"It's not a matter of weeks, it's a matter of days," he said.
Later on Wednesday, Iran's chief negotiator Ali Bagheri Kani struck an unusually optimistic note, saying that parties to the deal were "closer than ever to an agreement."
But Kani warned that negotiations could still fall through.
"Nothing is agreed until everything is agreed," he said in a tweet. "Our negotiating partners need to be realistic, avoid intransigence and heed lessons of past 4yrs."
"Time for their serious decisions," Kani added.
Iran and the United States are engaged in a final round of indirect talks -- mediated by China, Russia and European parties to the agreement -- over a return to the 2015 nuclear agreement, known as the Joint Comprehensive Plan of Action (JCPOA).
Analysts believe that failure to reach an agreement could lead violence in the crisis-ridden region to spiral out of control, with Iran fast approaching the nuclear threshold that would enable it to develop a nuclear weapon.
Tensions in the Middle East have escalated in recent weeks, with Iran-backed Houthi militants launching unprecedented missile and drone attacks on the United Arab Emirates, considered a haven of security in the volatile region. Saudi-led coalition forces fighting the militant group retaliated with the deadliest offensive on Houthi-held parts of northern Yemen in years, killing scores of people and knocking out the country's internet.
In his comments Wednesday, Le Drian warned that a breakdown in the Vienna talks would trigger a "serious crisis."
"Either [the Iranians] trigger a serious crisis in the days to come -- we could do without that -- or else they accept the agreement which respects the interests of all parties and particularly the interests of Iran," he said.
Le Drian said the two and half months of negotiations in Vienna was "exhausting diplomatic work."
Iran returned to indirect negotiations with the US shortly after President Joe Biden -- who promised to return to the deal as a presidential nominee -- took office. Iran had rejected repeated overtures by the Trump administration to return to the negotiations after the former president withdrew from the deal.