Iran Nuclear Talks Likely to Last until Thursday Morning: Source

The source, who is familiar with the talks, said the final deadline for the comprehensive accord falls on late Wednesday or the early hours of Thursday, July 9.

Earlier in May, US legislators passed a bill to have the right to review the possible nuclear deal. According to the bill, if the deal is submitted to the Congress before July 9, they would have a 30-day review period, and if submitted after July 9, the period would be extended to 60 days.

The extension of talks would come as Iran's Foreign Minister Mohammad Javad Zarif and US Secretary of State John Kerry have held several rounds of meeting over the past few days, and other foreign ministers are joining the talks in a last-ditch effort to strike a deal.

Last night, French Foreign Minister Laurent Fabius told reporters in the Austrian capital of Vienna that two days of intensive talks are ahead of nuclear negotiators.

Meantime, European Union Foreign Policy Chief Federica Mogherini told media representatives on Sunday that “if there is a time for a deal, it's now.”

“We are very close to a deal. The atmosphere in the talks is positive and good. I still see the political will to come to an agreement,” she stressed, adding that that political decisions have to be taken now.

Iran and the Group 5+1 (Russia, China, the US, Britain, France, and Germany) have been negotiating over the past 22 months to end more than a decade of impasse over Tehran's civilian nuclear program once and for all.

The two sides are busy negotiating in Vienna to clinch a comprehensive nuclear deal. The parties on Thursday gave themselves an extra week beyond an end-June deadline to nail down details of the long-awaited accord.

The long-awaited deal is expected to put an end to the anti-Iran sanctions that have obstructed Iran's trade with the world.