Iran and six world powers entered a crucial third day of talks Friday in Geneva, where they will try to close gaps on a proposed interim deal that would curb Tehran's nuclear program in exchange for sanctions relief.
Diplomats from both sides reported some progress following Thursday's session, but said substantial disagreements remain. The key sticking point appears to be to what extent Iran will be allowed to enrich uranium, participants said. Another is how much the sanctions will be relaxed.
Iranian Foreign Minister Mohammad Javad Zarif and Catherine Ashton, the European Union's top diplomat, have met repeatedly since Wednesday to work out differences.
The two talked on Friday. The morning negotiating session was not followed by the usual tidbits from Ashton's spokesman. Instead of characterizing the talks as "substantial" or "intense" as he did on Thursday, Michael Mann simply said they had ended, after about two hours.
Iran continues demands
Iran's official IRNA news agency, quoting Iranian Deputy Foreign Minister Abbas Araghchi in Geneva, repeated on Friday Iran's insistence that it retain the right to enrich uranium, a process that yields materials both for bombs and civil nuclear power generation.
Tehran denies it wants to build a nuclear weapon. It has offered to suspend parts of its nuclear program and agreed to tighter inspections if the West relaxes sanctions that have devastated its economy.
In an interview with Germany's ARD television, Mann said the negotiators need to reach a “sustainable” and “verifiable” agreement.
“We're always trying to be optimistic, but of course caution is necessary. I know I'm being very non-committal here, but in such a technical negotiation, such an important negotiation, it's best to be cautious," Mann said.
After the Friday morning meeting, Ashton briefed the delegations from the six nations representing the U.N. Security Council -- the United States, Britain, France, Russia, China and Germany. A U.S. official said the delegations then contacted their capitals for consultations.
Talks appear strained
The tone and sequence of events suggests that the talks continue to be difficult.
The two sides are seeking an initial agreement that would then leave six months to negotiate a more extensive deal to guarantee that the Iranian program is purely peaceful, as Iran claims, and to end all nuclear-related sanctions.
A former British ambassador to Iran, Richard Dalton, said both sides have a huge stake in reaching an agreement, and failure this week would be a serious setback.
“It would be extremely unfortunate, because as we've seen between second and third rounds both sides seem to have toughened up their position in some respects," he said. "So, if we see a failure now, it won't be any easier to find compromises.”
Dalton said the negotiators may have to try for a more limited first-stage accord if their current effort fails.
Meanwhile, there were reports that foreign ministers from the contact group, including U.S. Secretary of State John Kerry, might fly in and join the talks, extending them beyond their scheduled end Friday night.
The ministers did that during the last round of talks two weeks ago, but were not able to forge a deal.
If there is no agreement during this round, the negotiators are expected to gather again next month. There is pressure on both sides to take the first steps toward ending the nuclear dispute as soon as possible.
In Iran, hardliners are eager to declare the failure of the relatively moderate government that was elected in June with a mandate to seek an end to the sanctions.
And in the United States, a key member of the contact group, some members of Congress want to add sanctions to force Iran to make more concessions, a move the Obama administration says could kill any chance of a peaceful resolution to the dispute.