Vienna: Iran and six world powers got down to business in Vienna on Wednesday, groping for the elusive magic formula to secure a milestone nuclear deal that satisfies hardliners in Tehran and Washington.
The clock was ticking ever louder however on the second day of this final round of talks, with just five more days for Iran and the five permanent members of the UN Security Council plus Germany to get a deal.
Foreign ministers were expected in the Austrian capital later in the week, but the US State Department made clear that Secretary of State John Kerry, currently in London, would not arrive until Thursday afternoon at the earliest.
"Secretary Kerry will stay in London (on Wednesday) where he will continue consulting with both the negotiating team in Vienna and his interagency counterparts in Washington," spokeswoman Jen Psaki said.
Kerry will then head to Paris where on Thursday, he will hold separate meetings with foreign ministers of France, seen by many as one of the most hardline of the six powers regarding Iran, and of Sunni Saudi Arabia, worried about any US rapprochement with Shiite Iran.
Russian Foreign Minister Sergei Lavrov, whose country is a crucial player in the talks, will only come to Vienna if there is sufficient progress, Moscow`s lead negotiator Sergei Ryabkov told Russian media late Tuesday.
Upping the ante ahead of the deadline, Iran`s Foreign Minister Mohammad Javad Zarif, said a deal was "possible" but only if the six powers did not ask for too much.
"If, because of excessive demands... we don`t get a result, then the world will understand that the Islamic Republic sought a solution, a compromise and a constructive agreement and that it will not renounce its rights and the greatness of the nation," Zarif, who arrived in Vienna on Tuesday, told Iranian media.
But Kerry, who held the latest in a string of meetings with Zarif in Oman last week, put the onus on Iran.
"It is imperative that Iran works with us with all possible effort to prove to the world that the programme is peaceful," Kerry said.
British Foreign Secretary Philip Hammond echoed his comments, calling for more "flexibility by the Iranians to convince us that their intentions in their nuclear programme are entirely peaceful".The landmark accord being sought by Monday`s deadline, after months of negotiations, is aimed at easing fears that Tehran might develop nuclear weapons under the guise of its civilian activities.
It could resolve a 12-year standoff, silence talk of war, help normalise Iran`s relations with the West, boost the beleaguered Iranian economy and mark a rare foreign success for US President Barack Obama.
In order to make it virtually impossible for Iran to assemble a nuclear weapon, the US, China, Russia, Britain, France and Germany (the P5+1) want Iran to scale down its nuclear programme.
Iran, which insists its nuclear aims are exclusively peaceful despite failing to declare parts of its programme in the past, wants painful sanctions lifted.
Some areas appear provisionally settled. But the big problem is still enrichment -- rendering uranium suitable for power generation and other peaceful uses, but also, at high purities, for a weapon.
Iran wants to massively ramp up the number of enrichment centrifuges -- in order, it says, to make fuel for a fleet of future reactors.
The West wants the number slashed, saying Iran has no such need in the foreseeable future.
Other thorny issues are the duration of the accord and the pace at which sanctions are lifted, an area where Iranian expectations are "excessive", one Western diplomat said.Given the differences, many analysts expect more time to be put on the clock.
The alternative -- walking away -- would be "catastrophic" and "foolish", Arms Control Association analyst Kelsey Davenport told a news agency.
For now though, with another extension presenting risks of its own -- fresh US sanctions, not least -- officials insist that they remain focused on getting the job done in time.