Deadlocked Iran nuclear talks enter cliffhanger final weekend

The deadline for negotiations to expire has been set at November 24

Deadlocked international talks aimed at defusing a 12-year standoff with Iran over its nuclear ambitions entered their cliffhanger final weekend today, days before a deadline.

In a sign of the high stakes involved, US Secretary of State John Kerry and his Iranian counterpart Mohammed Javad Zarif stayed overnight yesterday in the Austrian capital Vienna in a bid to break the deadlock in a year-long round of rollercoaster negotiations.

But both sides said the gaps remained wide in the negotiations for a historic deal in which Iran would curb its nuclear activities in exchange for broad relief from years of heavy international economic sanctions.

Kerry had initially planned to depart temporarily later yesterday for Paris for consultations with his European counterparts before changing tack and holding a third late-night round of talks here with Zarif.

And Zarif had mulled returning to Tehran for consultations but he was quoted as saying by his delegation later that there were no 'significant' new proposals to make it worth the trip back home.

"We are running against the clock. Obviously, the deadline is Monday, and our folks there are working furiously to meet it... Serious gaps do remain," White House spokesman Eric Schultz said in Washington.

The gaps were so wide that Britain and Iran have raised the possibility that a final deal would not be reached by Monday's deadline, and a new set of negotiations launched.

Britain, the United States, Russia, China, France and Germany have been negotiating intensively with Iran since February to turn an interim accord reached a year ago into a lasting agreement by November 24.

Such a deal, after 12 years of rising tension, is aimed at easing fears that Tehran will develop nuclear weapons under the guise of its civilian activities -- an ambition the Islamic republic hotly denies.

A source close to the Iranian delegation told AFP the negotiators aimed for something short of a comprehensive nuclear agreement.

"Everybody is trying to find an agreement on a general framework so that we can work and fine-tune the details," the source said.

"There is no other scenario possible at this stage. Then we can give ourselves some time," the source added.