Officials say negotiations between Iran and six world powers are unlikely to yield a permanent accord on Tehran's nuclear program before a November 24 deadline despite a flurry of last-minute diplomacy.
"To reach a comprehensive deal seems physically impossible," Reuters quoted a European official as saying on condition of anonymity on November 23, a day before the self-imposed deadline to strike a deal. "Even if we were to get a political agreement, the technical annexes are not ready."
A member of Tehran's negotiating team in Vienna echoed that sentiment in an interview with Iran's ISNA news agency.
"Considering the short time left until the deadline and number of issues that needed to be discussed and resolved, it is impossible to reach a final and comprehensive deal by November 24," the Iranian official, whom ISNA did not identify, was quoted as saying in the report.
German Foreign Minister Frank-Walter Steinmeier suggested an extension of the talks could be in the works if no agreement is reached before the deadline.
"We are negotiating here with the ambition to reach an agreement," Steinmeier told Germany’s ARD television on November 24. "If this task should not be completed, one definitely would need to look at opportunities so that the road does not end here, but that the negotiating process can be continued."
The so-called P5+1 group of world powers -- comprised of the United States, Britain, France, China, and Russia plus Germany -- want a deal that ensures Iran cannot develop the capacity to build nuclear weapons.
In exchange, Iran wants crippling international economic sanctions to be lifted.
Iran and the P5+1 countries are "still far apart on many issues," Steinmeier told ARD.
U.S. Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif discussed a potential extension of the negotiations during their November 23 meeting in Vienna, Reuters quoted a senior U.S. State Department official as saying.
"Our focus remains on taking steps forward toward an agreement, but it is only natural that just over 24 hours from the deadline we are discussing a range of options both internally and with our P5+1 partners," the official told Reuters on condition of anonymity.
"An extension is one of those options," the official added after the meeting between Kerry and Zarif. "It should come as no surprise that we are also engaged in a discussion of the options with the Iranians."
The Iranian official quoted by ISNA said that discussions of extending the deadline are "on the table" if negotiators miss the deadline.
French Foreign Minister Laurent Fabius said earlier on November 24 that any agreement "has to be positive and enables us to work for peace."
"There are still differences to resolve," Fabius said.
Russian Foreign Minister Sergei Lavrov arrived in Vienna for the talks on the eve of the deadline and was to meet with Kerry as well.
Kerry also updated key regional allies on the negotiations. He briefed Saudi Foreign Minister Saud al-Faisal in person at the Vienna airport on November 23 and spoke by telephone with Israeli Prime Minister Benjamin Netanyahu a day earlier.
Netanyahu discussed the conversation at the beginning of his weekly cabinet meeting on November 23, saying Israeli officials “are anxiously monitoring developments in these talks.”
“Iran must not be allowed to be determined as a nuclear threshold state,” Netanyahu said. “There is no reason why it should be left with thousands of centrifuges that could enable it to enrich uranium for a nuclear bomb in a short time.”
Differences remain over the size and scope of the uranium-enrichment activities that Iran should be allowed to carry out.
Iran insists its nuclear program is only for peaceful, civilian purposes.
Kerry, who postponed a trip to Paris to stay in Vienna for talks, said a day earlier that negotiators were "working hard" toward "careful progress," but that "serious gaps" remained.
A European source close to the negotiations said on November 22 that the parties had made "no significant progress" in the talks and the "Iranians will have to move in a substantial way" in order to reach a full agreement.
That source, speaking to journalists on condition of anonymity, said the goal was to reach "a precise agreement."
Meanwhile, U.S. President Barack Obama said in televised comments broadcast by ABC News on November 23 that "significant gaps" remained with Tehran over its nuclear program. Obama, however, lauded the interim agreement that has facilitated the negotiations.
"So now the question is, can we get to a more permanent deal?" Obama said in an interview, which was conducted two days earlier.
Obama added that a permanent deal could help “begin a long process” of normalization in relations between Iran and other nations.
"I think ultimately that would be good for the people of Iran,” Obama said. “You know, it's a big country with a lot of talent, a lot of sophistication."