French President Francois Hollande has spelled out his key demands to Iran ahead of crunch nuclear talks between Tehran and world powers this week in Geneva aimed at reaching a landmark accord.
Speaking on Sunday in Israel, which has warned the West it will not abide by any deal it sees as weak, Hollande said ahead of talks starting Wednesday that Tehran had to take four "essential" steps.
"The first demand: put all the Iranian nuclear installations under international supervision, right now. Second point: suspend enrichment to 20 percent. Thirdly: to reduce the existing stock (of uranium)," Hollande said.
"And finally, to halt construction of the Arak plant. These are the points which for us are essential to guarantee any agreement."
The demands chime broadly with what diplomats say was presented to Iran late on the final day of the last talks between Iran and the United States, China, Russia, Britain, France and Germany -- the P5+1 -- on November 7-10.
But this was the first time that any of the countries involved has stated so publicly what they required of Iran.
Last time in Geneva, French objections necessitated a re-write of the proposal, sparking rumours of disunity among the powers, but diplomats and experts insist now that all six are singing from the same hymn sheet.
"Those four points are basically the package," Mark Fitzpatrick, analyst at the International Institute for Strategic Studies, told AFP.
Iran says it is enriching uranium to purities of up to five and 20 percent for civilian purposes. But when further enriched to 90 percent it can be used in a nuclear bomb.
Its stockpile of enriched uranium is large enough in theory to make material for several bombs, and Iran's ability to enrich to 20 percent is of particular concern because it is relatively easy to process it further to weapons-grade.
At present the UN atomic watchdog would detect any attempt to enrich to 90 percent, but the fear is that soon this may no longer be the case as Iran adds more and more centrifuges, including modern ones that enrich much faster.
Another worry is the reactor being built at Arak, which theoretically could provide Iran with plutonium, an alternative to highly enriched uranium in a bomb.
A 'real chance' for a solution
Even though it would only be a "first phase" initial deal, an accord in Geneva this week would be a landmark breakthrough after a decade of rising tensions and failed diplomatic initiatives.
Russian President Vladimir Putin called his Iranian counterpart Hassan Rouhani on Monday and was upbeat about the possibility of an end to the decade-old standoff over Tehran's nuclear drive.
"Putin stressed that a real chance has now emerged for finding a solution to this longstanding problem," the Kremlin said in a statement.
The UN Security Council has slapped four rounds of sanctions on Iran and additional US and EU sanctions in 2012 began to cause Tehran major economic problems.
Israel, itself widely assumed to have a formidable nuclear arsenal, has refused to rule out bombing Iran, as has Washington.
It remains to be seen, however, whether the minor and reversible sanctions relief that the P5+1 are offering in return will be enough to persuade Tehran to sign up to the deal.
Another potential sticking point is Iran's demand for the powers to recognise its "right" to enrich.
"No agreement will be reached without securing the rights of the Iranian nation," Iran's lead negotiator Abbas Araqchi said Sunday, predicting "difficult" talks.
Watching closely will be hardliners in both the United States and Iran, as well as Israel.
Any deal seen as too soft on Iran will make it even harder for US President Barack Obama to dissuade Congress from passing more sanctions on Iran, something which might scupper the negotiations.
Rouhani risks losing the backing of supreme leader Ayatollah Ali Khamenei if the moderate's "charm offensive" since taking office in August fails to bear fruit soon.
"If Rouhani is not getting anywhere the conservatives are going to make a strong comeback," Trita Parsi, author and president of the National Iranian American Council, told AFP.
Hollande's trip to Jerusalem was seen as an attempt to ease Israeli concerns that Iran would get what Prime Minister Benjamin Netanyahu has slammed as the "deal of the century" for its arch rival.
US Secretary of State John Kerry, who flew into the last round of Geneva talks with other foreign ministers, will attempt to do the same when he visits Israel on Friday.