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Iran nuclear talks come down to final weekend

Iran's chief nuclear negotiator Foreign Minister Javad Zarif is urging all parties to work together to broker a deal so that they can all move on to focus on their common enemy of "violent extremism and barbarism."

"The menace we're facing - and I say we, because no one is spared - is embodied by the hooded men who are ravaging the cradle of civilization," Zarif said in an English language YouTube video posted to Twitter and shot in Vienna, where the nuclear negotiations have been going on for several days and are about to conclude.

It was an unusually explicit call for the West to work with Iran to fight ISIS and al Qaeda. Zarif also said in the video, that "despite some differences that remain, we have never been closer to a lasting outcome."

But a senior Obama administration official dismissed the idea that the fight against ISIS had made its way into the negotiations, saying, "That's not what this is about." The official, who briefed reporters on the progress in the negotiations said that at this point are focused "exclusively on the core problem, which is the threat posed by Iran's nuclear program."

Most of the ministers have now left Vienna and expert groups are working through the details on both the nuclear aspects of the deal, as well as the sanctions. Secretary of State John Kerry and the foreign ministers from five other countries - Britain, China, France, Germany and Russia - will gather in Vienna probably on Sunday for what the official called "the end game of all of this."

Iran is prepared to allow weapons inspectors some access to its military sites, a senior official from Tehran said Thursday, although not "anytime, anywhere" inspections.

Determining the scope of access for International Atomic Energy Agency (IAEA) weapons inspectors remains the major sticking point, although Iran has signaled it may have a come up with a workaround that would allow IAEA inspectors "managed access" to suspect sites, but still allow Iran to protect its "military secrets."

Negotiators are also still working on the sequencing of the lifting of financial sanctions, so that once Iran is found to be in compliance with each requirement of the deal, the related sanctions could be suspended on the the same day.

If and when the parties reach an agreement, the text of the deal will be made public. Kerry has spoken on the phone with Sens. Lindsey Graham and Pat Leahy, and, the official said he would also be talking with other members, too.