Deadlocked Iran nuclear talks break off, to resume next week

By Louis Charbonneau and Parisa Hafezi LAUSANNE, Switzerland (Reuters) - Iran and six world powers suspended negotiations on a nuclear agreement and were set to meet again next week to break a deadlock over sensitive atomic research and lifting of sanctions, Western officials said on Friday. While the negotiations have made progress over the past year and both sides appear determined to push for a deal, differences on sticking points are still wide enough to potentially prevent an agreement in the end. France was demanding more stringent restrictions on the Iranians under any deal than the other Western delegations, officials said. On the sixth day of talks at a 19th century hotel in the Swiss city of Lausanne, plans for the delegations changed repeatedly over the course of several hours. At one point, the foreign ministers of France, Britain and Germany were expected to join the talks on Saturday. But less than an hour later, the Iranian delegation informed their U.S., British, French, Germany, Russian and Chinese counterparts that they were returning to Tehran due to the death of President Hassan Rouhani's 90-year-old mother on Friday. Tehran's delegation checked out of the hotel and headed to the airport. All sides agreed a resumption late next week was likely. Prior to the Iranian departure, U.S. Secretary of State John Kerry, Energy Secretary Ernest Moniz, Iranian Foreign Minister Mohammad Javad Zarif and Iranian Atomic Energy Organisation chief Ali Akbar Salehi held another series of meetings to break the impasse. In addition, technical and political experts from the parties have been gathering daily to discuss options that could form the basis of an agreement under which Iran would accept curbs on sensitive nuclear work for at least a decade and sanctions on it would be gradually eased. There was no breakthrough this week. Disagreements arose among the six powers, with France insisting on a longer period of restrictions on Iran's nuclear work. It also opposed the idea of suspending some U.N. sanctions relatively quickly if a deal is struck. Iran wants all U.N. sanctions, including those targeting its nuclear programme, to be lifted immediately. "They insist they have to go immediately. No way. It is out of the question," said a senior European negotiator, echoing concerns raised by the French. Zarif said the talks had reached a "very crucial point" and progress had been made this week. He also suggested the six powers needed to reach a unified position. "Given that Americans had officially said that further internal coordination meetings needed among the (six) members, the talks were ended and will resume next week in Lausanne," Iran's ISNA news agency quoted Zarif as saying. Kerry said they made good progress, adding: "We'll be back next week." Russia's chief negotiator Sergei Ryabkov told Reuters he agreed wholeheartedly with Kerry's assessment. During that meeting, Kerry expressed condolences to the delegation for the passing of Rouhani's mother and greetings for the Iranian new year holiday Norouz, which begins on Saturday. U.S. President Barack Obama prepared a video message to Iran's people and leaders on Thursday, saying this year represented the "best opportunity in decades" to improve ties between their two countries. But differences in the nuclear talks remained, he said. Western and Iranian officials have said that the sides are very far apart, though all delegations want a deal. "The alternatives to a negotiated agreement are not very pleasant," a Western official told Reuters. "No one wants to give up. We all want and need this deal." But U.S. and European officials say they only want a solid agreement that ensures Iran will not be able to quickly build an atomic weapon. Tehran denies harbouring nuclear weapons ambitions. POLITICAL FRAMEWORK The European ministers and Kerry plan to meet in London on Saturday before the end-March deadline for a political framework agreement and a full nuclear deal by June 30. "For us the deadline is June 30," the senior European official said. The London meeting is intended to bridge differences among the Americans and Europeans. Officials close to the talks have expressed concerns that the French might block a deal. Deputy Foreign Minister Abbas Araqchi said the talks would resume on Wednesday. This week's re-election of Israeli Prime Minister Netanyahu, a fierce opponent of engagement with Iran and critic of a possible nuclear deal, made clear that the pressure on the United States would not let up. Pressure from the U.S. Congress is also driving the pace of negotiations. Obama bought some time on Thursday after U.S. Senate Democrats and Republicans agreed to delay until April 14 the Senate Foreign Relations Committee's vote on legislation that would force Obama to submit any agreement with Iran for Congress' approval. Obama has said a nuclear deal does not need Congressional approval and said he would veto any proposals for new U.S. sanctions. A further meeting of foreign ministers from the Western powers this weekend will demonstrate unity in the face of the deadlock and give ministers the opportunity to coordinate, a source close to the talks said. Chinese Foreign Minister Wang Yi told Kerry the talks "must not fall short for lack of a final effort", China's Foreign Ministry said after the two spoke on the telephone. Russian news agency Interfax reported that Foreign Minister Sergei Lavrov and Kerry agreed that an acceptable solution to the standoff must be found as soon as possible. The biggest sticking point, Western officials said, remains Iran's demands to have no limits on research and development of advanced centrifuges, machines that purify uranium for use in nuclear reactors or, if very highly enriched, in weapons. Another is the lifting of sanctions. Iran wants all United Nations sanctions and the most crippling U.S. and European Union restrictions on Tehran's energy and financial sectors lifted immediately after a deal is agreed. A further area of disagreement is the duration of a deal. Obama has said restrictions on Iranian nuclear work should be in place for at least 10 years. U.S. negotiators are pushing to make it longer than that, while France wants it to last for at least 15 years with another decade of intense U.N. monitoring of Iranian nuclear sites. There are a few areas of tentative agreement, including that Iran could operation around 6,000 early generation centrifuges. But officials close to the talks dismissed reports of a tentative deal, saying they were very far from circulating anything remotely resembling a draft accord. (Additional reporting by John Irish and Lesley Wroughton; Writing by Louis Charbonneau and Parisa Hafezi; Editing by Giles Elgood)