VIENNA — With a deadline for a nuclear deal less than two days away, negotiators faced the choice Sunday of pushing on despite diminishing chance of agreement, or shifting to ways of extending negotiations past the target date.
A member of the Iranian delegation in Vienna said the tipping point could come Sunday night, with Iran and six world powers deciding that their differences are too big to bridge by Monday and switching to extension mode.
From that point on, he said, the negotiations would focus on reaching a "general political agreement" on what both sides are committed to resolving. The official, who demanded anonymity as a condition for briefing the media, said that talks would then be held in the near future to sign that agreement, leading to more negotiations on outstanding issues.
Should such a plan be agreed upon, one possibility for a resumption of talks would be the first week in December when U.S. Secretary of State John Kerry plans to return to Europe for a previously scheduled NATO foreign ministers meeting in Brussels, and an international conference in London.
Diplomats familiar with the negotiations said sizable gaps remain between the U.S. and Iran on the key issue of how deeply Tehran would have to reduce nuclear activities that could be turned to making arms.
Iran denies any interest in such weapons, but is negotiating because it wants an end to nuclear-related international sanctions.
The talks are confidential, but President Barack Obama outlined the differences between Washington and Tehran in general terms.
"I think that our goal has consistently been to shut off a whole bunch of different avenues whereby Iran might get a nuclear weapon, and at the same time make sure that the structure of sanctions are rolled back step for step as Iran is doing what it's supposed to do," he told ABC's "This Week" in an interview aired Sunday.
"I think Iran would love to see the sanctions end immediately, and then to still have some avenues that might not be completely closed, and we can't do that."
As the clock ticks down, foreign ministers for most of the seven nations taking part in the Austria talks are converging in a concerted effort to get a deal.
Since his arrival Thursday, Kerry has met repeatedly with Iranian Foreign Minister Mohammad Javad Zarif and other key officials.
Germany's foreign minister landed Saturday, while his counterparts from Russia, France and Britain were due to join him later Saturday. China's foreign minister was scheduled to arrive Monday.
Kerry also met with Saudi Foreign Minister Saud al-Faisal, whose country is vying for Middle East influence with Iran. Diplomats said Saud flew to Vienna from Paris solely for the briefing, planned to leave immediately afterward, and the two talked in his plane parked on the Vienna Airport tarmac.