Iran and world powers struck late Friday a deal to extend their Sunday deadline to strike a nuclear accord easing fears Tehran will get the bomb, an Iranian and a Western diplomat said.
"Negotiations on the extension of the Geneva (interim) deal have been successful. The details of the agreement will be announced soon," the Iranian source said.
The Western diplomat confirmed the agreement, saying that the parties have given themselves until November 24 to strike what would be an historic deal.
"It's until November 24," the diplomat said.
More details of the agreement were expected in a news conference later Friday in Vienna.
Iran and the six powers have been negotiating almost constantly for months, trying to forge an accord by July 20 when an interim deal agreed in Geneva in November expires.
After a decade of rising tensions, the mooted accord between Iran and the five permanent members of the UN Security Council plus Germany is aimed at easing concerns that Iran might develop nuclear weapons and silencing talk of war.
Iran denies seeking the atomic bomb and wants the lifting of crippling UN and Western sanctions.
The six powers want Iran to dramatically reduce in scope its nuclear programme for a lengthy period of time and agree to more intrusive UN inspections.
This would greatly expand the time needed for the Islamic republic to develop a nuclear weapon, should it choose to do so, while giving the world ample warning of any such "breakout" push.
Washington and Iran earlier this week laid the groundwork for pushing back the deadline after US Secretary of State John Kerry held two days of intense talks with his Iranian counterpart that failed to produce a breakthrough.
"It's clear that we've made real progress in several areas and that we have a credible way forward, but as we approach a deadline under the interim deal, there is still significant gaps between the international community and Iran and we have more work to do," US President Barack Obama told reporters on Wednesday.
The two sides are believed to have narrowed their positions in recent weeks on a few issues such as the Arak reactor, which could give Iran with weapons-grade plutonium, and enhanced inspections.
But they remain far apart on the key issue of Iran's capacities to enrich uranium, a process which can produce fuel for reactors but also the core of a nuclear bomb.
The six powers want Iran to reduce dramatically the scope of its enrichment programme, while Tehran wants to expand it.
- Domestic pressure -
The US and Iranian governments are both under intense domestic pressure not to give too much away.
US lawmakers, who are widely supportive of Israel, have threatened to ramp up sanctions without a rigorous agreement.
Senator Robert Menendez, a member of Obama's Democratic Party who chairs the Senate Foreign Relations Committee, has called for an accord that dismantles Iran's nuclear program in a way that is verifiable for 20 to 30 years.
Iran's negotiators in turn face pressure from hardliners, who view the United States as the ultimate enemy and oppose any agreement seen as a concession.
Israel, the Middle East's sole if undeclared nuclear armed state and which together with Washington has refused to rule out military action, is opposed to any enrichment by Iran at all.
"Progress has been achieved in several areas, but gaps remain on several issues. Negotiators will need time and flexibility from political leaders in their capitals," said Kelsey Davenport at the Arms Control Association.