VIENNA — With only three days to go before a deadline to reach an international accord to constrain Iran’s nuclear program, the talks here appeared to be marked by brinkmanship Friday, as Iran’s top negotiator appeared headed back to Tehran — but later said that he was staying.
Iranian news agencies had reported that Mohammad Javad Zarif, Iran’s foreign minister, was going to Tehran to seek further instructions.
The State Department’s spokeswoman announced soon afterward that Secretary of State John F. Kerry would leave for Paris, where he would confer with European officials and stay in touch with Obama administration officials in Washington.
But Zarif later told Iran’s official IRNA news agency that “there were no remarkable offers and ideas to take to Tehran.” That led Kerry to shelve his plan to leave, too.
US and European officials vowed to press on, and more high-level negotiating sessions were expected Saturday.
Yet the difficulties in the talks suggested that if an agreement is announced Monday, it probably would not be a complete one, and an extension in the deadline is growing more likely.
“We’ve been very candid that real differences remain and we’re not going to discuss an extension prematurely with the Iranians because that takes pressure off of them to wrestle with tough issues now,” said a senior State Department official, who declined to be identified.
The negotiations in Vienna involve senior diplomats from Iran and the United States, France, Britain, Germany, Russia, and China.
The Obama administration’s goal is to conclude an agreement that would slow the Iranian program to the point that it would take Iran at least a year to make enough fissile material for a nuclear bomb if Tehran later decided to ignore the accord.
Several key obstacles stand in the way of an agreement. One is how much capacity Iran could retain to enrich uranium, an issue that encompasses the size of its nuclear stockpile and the number of centrifuges that could remain installed.
The second centers on Iran’s demand that economic sanctions be permanently lifted and not just suspended step by step as Iran complies with the terms of the deals.
Kerry joined the talks here on Thursday and has held three joint meetings with Zarif and Catherine Ashton, the European Union’s envoy to the talks.
Kerry consulted also here on the next steps in the talks with Laurent Fabius, the French foreign minister, and Philip Hammond, the British foreign secretary, who flew here Friday. Hammond later reported that there was “a very significant gap between the parties.”
US officials hope that a successful negotiation would ease tensions with Tehran and discourage other nations in the region from pursuing nuclear arms, while enhancing the Obama administration’s legacy on foreign policy.
But the negotiations also are being watched with a wary eye by Israel, Saudi Arabia, and many US lawmakers, who fear that a new accord may allow Iran to maintain too much of its nuclear infrastructure and potential bomb-making capability.
Talks last year in Geneva to draft an interim agreement to freeze much of Iran’s nuclear program went down to the wire, but ultimately resulted in an accord. If the negotiating deadline to complete a more comprehensive and enduring agreement were extended, it would be the second time this year.
In a news conference Thursday in Paris, Kerry sought to justify the time it has taken to pursue a comprehensive accord.
“It was only last year when our nation first resumed high-level contact after decades of stalled relations,” he said.
At the same time, Kerry was also adamant that the United States was not seeking an extension in the Monday negotiating deadline.
“We are driving toward what we believe is the outline of an agreement that we think we can have,” Kerry said.
Hammond was more open earlier this week in acknowledging that some sort of extension of the negotiating deadline might be needed.
During a trip to Latvia, Hammond said he was not optimistic that a comprehensive agreement could be finalized by Monday, but expressed the hope that there might yet be “some significant movement” that might warrant yet another deadline extension.