VIENNA—Nuclear negotiations between Iran and six world powers have reached the make-or-break point, European officials said, warning the diplomacy could fail if there is no final agreement by Monday night.
The comments by senior European diplomats in Austria’s capital on Sunday suggested a divergence from Washington on the way forward with Tehran.
The Obama administration has also said it is willing to end nearly two years of negotiations if a deal isn’t struck in the coming days to prevent Iran from acquiring nuclear weapons in exchange for sanctions relief.
But senior White House officials have also indicated the U.S. wasn’t going to be rushed into a final agreement and it might be willing to roll over an interim accord signed with Tehran in late 2013. That deal locks in modest sanctions relief for Iran and freezes parts of their nuclear program.
If a deal isn’t reached by Monday night, a European official said there was “no way” the negotiations can continue.
The State Department said Sunday that “major issues” sill needed to be resolved, but U.S., Iranian and European officials all said talks were down to the final issues and a deal was possible on Monday.
Among the final issues to be resolved are disagreements about the exact timing and sequencing of sanctions relief for Iran and the continuation of an arms and ballistic-missile ban. Officials have also been working on the text of a new United Nations Security Council resolution keeping some restrictions on Iran and outlining steps the country will take to shed light on its past nuclear activities.
Leading Republican lawmakers also said Sunday that they preferred the U.S. extending the talks rather than President Barack Obama agreeing to a deal that would still leave Iran with the capabilities to make nuclear weapons.
“Everything can fail still, but we are really near the end,” said a German official late Sunday. “With the willingness of Tehran to take the final steps, it could now go quickly. We are ready to negotiate all night.”
French Foreign Minister Laurent Fabius indicated in Vienna over the weekend that Paris believed Iran had been given enough time to make the political decisions needed to conclude an agreement.
“Now that everything is on the table, the moment has come to decide,” he told reporters on Saturday.
In the past, French officials have said that if Iran wasn’t willing to strike a deal now, negotiations could go on hold until Tehran, which is eager to win major sanctions relief, proves more amenable to a deal.
It remains unclear, however, whether the European delegations would really be prepared to leave Vienna if pressed hard by Washington to stay.
The European Union foreign policy Federica Mogherini chief said on Twitter Sunday that the talks had reached their “decisive hours.”
The U.S. and its negotiating partners—Russia, China, France, Germany and the U.K.—have already missed three deadlines during more than two weeks of direct talks with Tehran. Western officials have set a new deadline of Monday night to finish the talks, but U.S. diplomats have indicated it was only a soft target.
U.S. Secretary of State John Kerry has held extensive negotiations with his Iranian counterpart, Javad Zarif, over the past two weeks. Mr. Kerry and Mr. Zarif met only once Sunday, a 37-minute discussion in the evening, according to U.S. officials.
Still U.S. officials say they’re not certain whether Iran’s most powerful political figure, Supreme Leader Ayatollah Ali Khamenei, fully supports his negotiators. On Saturday, Mr. Khamenei said his country would maintain its opposition to the world’s great “arrogant” power, a code word for the U.S.
Iranian officials said over the weekend negotiations were proceeding toward a conclusion while Mr. Zarif said the work would continue on Monday.
The nuclear diplomacy is a central foreign-policy goal of the Obama administration while Iranian President Hasan Rouhani has made the diplomatic outreach and a lifting of international sanctions the central goal of his term.
A final agreement was supposed to be locked in on June 30. The deadline was then moved to July 7, July 10 and now to Monday. Iran has warned if the talks break down, it could quickly rev up its nuclear activities.
Iranian and Western officials have said in recent days that most of the text of an agreement, which is likely to include a main text and five annexes, had been agreed upon.
On Sunday morning, Mr. Kerry attended church in Vienna and then took a brief, impromptu walk from the Palais Coburg hotel, where the negotiations are taking place, to the Mozarthaus, where composer Wolfgang Amadeus Mozart lived from 1784-7 and where he composed his famous opera The Marriage of Figaro.
Mr. Kerry has been on crutches for much of the last few weeks after breaking his leg in May.