World powers will meet for fresh talks with Iran on its controversial nuclear programme on Tuesday, amid mounting hopes of a less hardline approach from the new Tehran government.
The two-day meeting in Geneva will be the first such negotiations since President Hassan Rouhani, a reputed moderate, took office in August.
Rouhani has pledged to engage the world constructively to resolve the decade-long showdown over Iran's nuclear ambitions and ultimately secure the lifting of crippling Western sanctions.
Western governments and Israel suspect Iran is seeking a nuclear weapons capability, an ambition repeatedly denied by the Iranian leadership.
Foreign Minister Mohammad Javad Zarif has taken over as Iran's lead negotiator with the so-called P5+1 group of the Britain, China, France, Russia and the United States plus Germany.
But so far he has been tight-lipped about what Iran is prepared to offer in exchange for relief from EU and US sanctions which have badly hit Iran's oil exports and its access to global banking.
"We will present our views, as agreed, in Geneva, not before," Zarif said in a tweet on Friday.
His deputy in the talks, Abbas Araqchi, however, set out a red line for Tehran in the negotiations, insisting today that there could be no question of Iran relinquishing its stocks of enriched uranium, which are the focus of many of the West's concerns.
"We will negotiate about the volume, levels and the methods of enrichment but shipping out the (enriched) material is a red line for Iran," Araqchi told the state broadcaster.
Uranium needs to be enriched to levels of above 90 per cent for use in a nuclear warhead.
Only low levels of enrichment are required to provide the fuel for nuclear power plants, while Iran says it also needs uranium enriched to 20 per cent for a medical research reactor it operates.
It is the 20 per cent enriched uranium that is the source of the greatest international concern, as Western governments fear Iran could covertly divert some of it for further enrichment towards weapons grade.
Iran currently has a stockpile of 6,774 kilogrammes of low-enriched uranium, and nearly 186 kilogrammes of material enriched to 20 per cent level.
Iran also possesses some 187 kilogrammes of the 20 per cent material converted to uranium oxide for use in fuel plates.
Iran insists it has the "right" to enrich uranium for peaceful purposes and has defied repeated ultimatums from the UN Security Council to suspend all enrichment.
A source close to Iran's negotiators told the official IRNA news agency that they would submit to the powers "a clear path" for the talks, and include a timetable and a framework with "specified first and last steps.
