Vienna: World powers got back to work Tuesday seeking to nail down an elusive nuclear deal ending a 13-year standoff with Iran, only hours before another deadline expires.
After talking deep into the night Monday, foreign ministers from the so-called P5+1 group leading the negotiations met briefly again Tuesday without the Iranian delegation.
The group -- Britain, China, France, Germany, Russia and the United States -- is seeking to hammer out a final accord to put an atomic bomb out of Iran`s reach.
But Tuesday`s deadline for a deal -- the fourth since an interim deal was struck in November 2013 -- looked almost certain to be missed, as the ministers grappled with the toughest remaining issues which have so far thwarted an accord.
In what has become a high-stakes game of diplomatic poker, the ministers met twice Monday with the Iranian delegation led by Foreign Minister Mohammad Javad Zarif for a total of almost three hours.
Asked whether Tuesday`s deadline may slip, White House spokesman Josh Earnest said: "I would say that it`s certainly possible."
State Department spokesman John Kirby told reporters in Washington that Tuesday was "not a deadline. It was an extension of basically seven days of the parameters" of an April 2 framework accord struck in Lausanne.
But he refused to be drawn on what might happen on Tuesday, insisting: "Everybody is still I think rowing on the oars here to try to get a deal done, but it`s got to be the right deal."
An Iranian official also made it clear on Monday that "July 7, July 8, we do not consider these dates as those dates we have to finish our job."
"Even if we pass July 9, that will not be the end of the world," the Iranian said, asking not to be identified.
US Secretary of State John Kerry is under pressure to present a deal to Congress by Thursday, so American lawmakers have 30 days to debate it.
If the accord comes later, then under a new law there will be a 60-day review period.
Despite progress on a series of complicated annexes, negotiations have bogged down on how to ease sanctions against Iran, probing allegations that in the past Tehran sought to develop nuclear arms, and ensuring Iran can continue to have a modest, peaceful nuclear programme. Seeking to resolve lingering suspicions that Iran before 2003, or maybe after, had sought to develop nuclear arms, UN nuclear monitors were in Tehran on Monday.
The 24-hour visit by experts from the International Atomic Energy Agency (IAEA) came after a similar trip last week by its director general Yukiya Amano.
Behrouz Kamalvandi, spokesman for Iran`s Atomic Energy Organisation, said Monday`s talks were a "major step" towards resolving outstanding issues and were "constructive and forward-looking".
The second IAEA visit "shows the serious determination of both sides to enhance cooperation", he said, quoted by the official IRNA news agency.
There was no immediate comment from the IAEA.
But in what appeared to be a new spanner in the works, the Iranian official said his country also wanted to ensure there was no renewal of a UN "arms embargo".
"There is no evidence that the arms embargo has any relation with the nuclear issue," the official said.
"The arms embargo should not be part of" the deal under negotiation, he said.
A fact sheet put out by the State Department after the April accord said that once any deal is reached there would be a new UN Security Council resolution to extend "important restrictions on conventional arms and ballistic missiles".
Western officials are clearly balking at any notion of allowing Iran to buy conventional weapons, at a time when it is accused of fomenting unrest in the Middle East.