File Photo: Iranian Foreign Minister Mohammad Javad Zarif along with his counter parts at meeting at the hotel where the Iran nuclear talks are being held in Vienna, Austria July 6, 2015. (Reuters)
Foreign ministers from major powers sought today to turn the screws on a hard-bargaining Iran to finalise a historic nuclear deal on the eve of a deadline to present it to US lawmakers.
If the US Congress does not receive the text by early on Friday morning Vienna time -- midnight in Washington -- it makes the approval process longer and potentially more problematic.
But despite this pressure, and almost two weeks of talks in the Austrian capital, it is unclear whether an accord aimed at ending a 13-year standoff can be sewn up at all.
US President Barack Obama held a video conference on Wednesday with the US negotiators and "reviewed the progress of negotiations to date, and provided guidance" to the team, the White House said.
But Obama had reportedly told senators on Tuesday that the chances of an accord were "less than 50-50."
Building on a framework agreement from April, the deal would see Iran dismantle large parts of its nuclear infrastructure in order to put a nuclear bomb out of reach.
In return, a web of painful sanctions on Iran -- which denies wanting the bomb -- would be progressively lifted once the UN atomic watchdog verified Tehran had fulfilled its promises.
"Never have Iran and its counterparts been this close to a final accord. But success is far from assured... Serious political decisions still need to be made," Iranian Foreign Minister Mohammad Javad Zarif wrote in the Financial Times.
A spokesman for the Iranians said he did not rule out that the talks might run for several more days.
US Secretary of State John Kerry quipped today at the start of a new meeting that they were in "Groundhog Day".
"Hopefully today (Thursday) is the last day," Iranian nuclear chief Ali Akbar Salehi said as he met US Energy Secretary Ernest Moniz.
Difficult issues in what will be a highly complex agreement include working out the pace and timing of sanctions relief and a stalled UN probe into alleged efforts by Iran to develop the atomic bomb.
Iran has also insisted there should be changes to a UN arms embargo and an easing of restrictions on missile sales, a prospect alarming rivals of Iran and allies of the United States in the region.
Russian Foreign Minister Sergei Lavrov said from a BRICS summit in Ufa, Russia that he supported lifting the arms embargo "as one of the first sanction measures (to be lifted)".
The goal of the sanctions of getting Iran to negotiate had "long been reached" and arms would help Tehran combat Islamist State extremists -- a common enemy for the US, Iran and Russia.
'No Unsurmountable Problems'The foreign ministers of Britain, Germany and France rejoined the talks today, with lower level officials sitting in for the Chinese and Russian ministers, whose return is not yet scheduled.
Kerry and Zarif also then met for 40 minutes -- their first meeting since Tuesday, US officials said.
Lavrov said from Ufa -- where Russia's chief negotiator in the Iran talks was also present -- there were no "unsurmountable problems" remaining, and that he might rejoin "at any moment".
Kerry spoke by phone with Chinese Foreign Minister Wang Yi.
A deal with the P5+1 group -- the United States, Russia, China, Britain, France and Germany -- could pave the way to normalised relations between Iran and the West after 35 years of mistrust and enmity.
If Congress does not get the deal in time, the review period doubles to 60 days, giving opponents more time to reject it, and the whole process could stretch to 82 days.
During this time Obama cannot waive Congressional sanctions, which are the most painful ones for Iran.
Expert Suzanne Maloney at the Brookings Institution said that she does not expect Congress to "upend a multilateral deal".
Where US lawmakers could however "create problems", however, is in the tricky next phase after the deal is agreed and approved: implementation.