On Friday there had been reported that Zarif might go back to Tehran to consult with top officials.

Talking to reporters, Zarif said,' there have been a lot of discussions in the talks, but there have been no new ideas or remarkable proposals to take to Tehran.'

The tenth and last round of nuclear talks between Iran and the Group 5+1 has started since Tuesday in Vienna. The two sides are trying to reach an agreement until November 24.

Foreign Ministry spokeswoman Marziyeh Afkham

Foreign Ministry spokeswoman Marziyeh Afkham termed certain news making on the new G5+1 proposal to Iran as baseless.In a statement issued Friday night, she noted that numerous compact talks, both at bilateral and multilateral levels, were underway in the past three days based on plans and initiatives put forward by the Iranian nuclear negotiating team, the latest of which was introduced in Muscat.

She added that the negotiations are still continuing at expert and political levels and stressed that 'no new proposal has been extended to Iran by G5+1.'

Some western media made news about new plans and proposals to Iran by the UK secretary of state for foreign and commonwealth affairs during the ongoing nuclear talks in Vienna.

Negotiation aimed at solving differences between Iran and west over Tehran’s civilian nuclear activities entered final weekend on Saturday, 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 Friday in the Austrian capital Vienna in a bid to break the deadlock in a year-long round of negotiations.

Both sides said the gaps remained wide in the negotiations for a historic deal in which Iran would be relief from years of cruel sanctions in exchange on reaching a deal on extent of enrichment and centrifuges.

US Secretary of State John Kerry arrived on November 20 in Vienna to join nuclear talks with Iran which take place in Palais Coburg.

Kerry had initially planned to depart temporarily later Friday 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 Friday 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.   
   
'Serious gaps'
   
"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, AFP reports.

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.

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.

British Foreign Secretary Philip Hammond had raised the possibility of a delay even if Kerry had said he intended to seal a deal here.

"We are not discussing an extension. We are negotiating to have an agreement. It's that simple," Kerry said in Paris Thursday before he went to Vienna.

Hammond left Vienna in the afternoon -- saying there was still a "very significant gap" -- but French Foreign Minister Laurent Fabius was still in the Austrian capital after meeting Zarif for an hour and a half.

Hammond called for more flexibility from the Iranians and said that "in return we're prepared to show some flexibility on our side".

French Foreign Minister Laurent Fabius and Iranian Foreign Minister Mohammad Javad Zarif hold bilateral talks on the sidelines of nuclear talks days before a deadline in the Palais Coburg in Vienna on November 21, 2014.

Fabius, seen as one of the most hardline among the six powers, called on Iran to "seize this opportunity".

Russian Foreign Minister Sergei Lavrov, a crucial player, said from Moscow that "all the elements are already on the table" for a deal and that all that was missing was "political will".

Kerry later "updated Foreign Minister Lavrov on the state of negotiations" by phone, the US official said.

Iran believes that the onus on the side of the world powers to compromise. Zarif and President Hassan Rouhani both warned the powers not to sink the talks with "excessive demands".
   
Complex deal

Two key issues remain: enrichment -- a process that renders uranium suitable for peaceful uses -- and the pace of the lifting of sanctions.

Iran wants to massively ramp up the number of enrichment centrifuges in order to make fuel for a fleet of future reactors while the West wants them dramatically reduced.

Kelsey Davenport, an expert at the Arms Control Association, said there was "still a lot of time until Monday at midnight".

Comments indicating flexibility on both sides show that "both parties are coming into these final days willing to look at their positions and make some decisions about the remaining tough issues," she told AFP.