As he met once again with his Iranian counterpart Mohammad Javad Zarif in Vienna, the US secretary of state insisted that while difficult issues remained they were making progress before a new Tuesday deadline for an accord, AFP reported.
The Iranian president Hassan Rouhani’s chief of staff, Mohammad Nahavandian, was headed to the negotiations on a “special mission”.
Kerry said: “We have some tough issues, but there’s been a genuine effort by everybody to be serious about this and to understand the time constraints that we’re working under.”
World powers are trying to draw the curtain on almost two years of negotiations, which gathered new impetus after Rouhani took power in late 2013. A deal would end a 13-year standoff with Iran over its nuclear program, AFP said.
Kerry is under pressure to send any deal to the US Congress by 9 July to give them 30 days to review it. If the deal is reached after 9 July, the Republican-controlled body would have 60 days to vote to approve or disapprove of the deal.
The teams were working “very diligently all day in order to maximize progress” and with “a great sense of purpose,” Kerry said.
Many of the ministers from the negotiating global powers – Britain, China, France, Germany, Russia and the US – are due back in Vienna on Sunday.
Zarif said: “We’re all trying very hard in order to be able to move forward and we have made some progress. There are still tough issues to discuss and to resolve but I think, with political will, we will.”
The chief negotiators of Iran, the US and the European Union haggled for six hours until 3am on Friday, a senior US official said.
“It feels like the end,” said one western diplomat. “The technical work is advancing on the main text, on the appendices.”
In exchange for scaling back its nuclear program, Iran is seeking a lifting of sanctions.
On Thursday Russia’s top negotiator, Sergei Ryabkov, voiced cautious optimism, saying a complex text and annexes were “91%” finished.
“I can’t predict how many hours it will take to resolve this situation. But all parties are of the opinion that this matter will be resolved in the coming days,” Ryabkov, the deputy foreign minister, told the Russian news agency Tass.
It will be up to the International Atomic Energy Agency, the UN watchdog, to verify that Iran is sticking to its side of the bargain through enhanced inspections of Iran’s nuclear facilities.
Iran rejects the allegations of a covert grab for a bomb, saying they are based on bogus intelligence provided to a gullible and partial IAEA by the likes of the CIA and the Mossad, Israel’s intelligence agency.
Abbas Araqchi, Iran’s lead negotiator in Vienna told Iranian media on Friday that Tehran was “ready to cooperate with Mr Amano so that it can be proved that these accusations and claims … are baseless”.