World powers and Iran are set to meet in Vienna Monday for talks on supplying the Islamic Republic - which the West accuses of seeking to build an atomic bomb - with nuclear fuel.
The talks, scheduled to begin at 1500 [1300 GMT], are seen as crucial to resolving the long-running standoff over Tehran's disputed nuclear drive because it will require Iran to hand over most of its enriched uranium, which it has amassed in defiance of U.N. resolutions, to a foreign country.
Attending the talks, which the International Atomic Energy Agency said could run to Tuesday or Wednesday, will be officials from France, Iran, Russia, the U.S. and the IAEA itself.
They will discuss the modalities for a plan put forward earlier this month whereby Iran will allow Russia and France to further enrich the uranium to levels required to fuel a research reactor in Tehran which makes isotopes for medical uses such as cancer treatment.
Enriched uranium is the most controversial aspect of Iran's atomic program, as it can be used as fuel for a nuclear reactor or, in much purer form, as the fissile core of an atomic bomb. Iran has so far amassed around 1,500 kilograms of low-enriched uranium at its plant in Natanz, in spite of repeated calls by the U.N., and three rounds of U.N. sanctions, for a halt to all enrichment activity, until the IAEA can determine the activities are entirely peaceful as Tehran says.
But Iran needs medium-enriched uranium to run the research reactor and the fuel for that reactor is running low.
The meeting Monday is the fruit of Oct. 1 talks in Geneva, at which Iran agreed to ship low-enriched uranium abroad for further purification and subsequent return to Iran.
Diplomats have described the proposal as a "win-win" situation: the Iranians would get the fuel they needed, while at the same time, Western fears would be allayed the material could be used to make a bomb.
In Tehran, the Iran Atomic Energy Organization insisted it would still not halt its enrichment activity in Natanz, whatever the outcome of the talks. Furthermore, it would even enrich its stockpile of uranium to the level required if the talks failed.
"The Islamic Republic of Iran...will continue its enrichment activities inside Iran up to the 5% level," the official IRNA news agency quoted the organization's spokesman Ali Shirzadian as saying. "But if the negotiations do not yield the desired results, Iran will start enriching uranium to the 20% level for its Tehran reactor. It will never give up this right."