Talks between world powers, including the U.S., on crafting a deal aimed at keeping Iran from developing nuclear weapons will extend through Monday as negotiators work to reach an agreement.
Iran's foreign minister said on Friday that talks between Iran and the six major powers had made some progress but were likely to continue during the weekend. The European Union confirmed to NBC that European sanctions on Iran have been extended until Monday to provide more time for talks on a final deal.
Iran and six powers — Britain, China, France, Germany, Russia and the United States — are trying to end a more than 12-year dispute over Iran's atomic program by negotiating limits on its nuclear activities in exchange for sanctions relief.
Related: Kerry: Nuclear deal must 'stand the test of time'
The sides remain divided over issues that include a U.N. arms embargo on Iran which Western powers want to keep in place, access for inspectors to military sites in Iran and answers from Tehran over past activity suspected of military aims.
"Some progress has been made but we are not there yet ... I doubt it will happen today ... it seems that we are going to spend the weekend in Vienna," Mohammad Javad Zarif told reporters.
The current round of talks has missed two deadlines already and was extended until Friday. Since that deadline was missed, a congressional review period will double from 30 to 60 days, possibly delaying the sanctions relief that the U.S. would have to give to Iran under the terms of an agreement. Republicans in Congress have expressed skepticism about the nature of the deal and whether Tehran will hold to any agreement.
Related: Iran nuclear talks: Kerry, Zarif locked in meetings as deadline looms
On Thursday Secretary of State of John Kerry speaking from Vienna stressed that while negotiators working to craft a nuclear deal with Iran would not continue working indefinitely, they are making progress toward a comprehensive deal.
"We believe we're making real progress," Kerry said. "But, as I've said many times and discussed with President Obama, we're not going to sit at the negotiating table forever."
Nor would negotiators rush through the delicate work of hammering out a framework, Kerry said.
"We also recognize that we shouldn't get up and leave simply because the clock strikes midnight," he said. And I emphasize, given that the work here is incredibly technical and that the stakes are very, very high."