Nejad made the declaration at the exhibition of Laser Science and Technology Achievements in Tehran, asking Ali Akbar Salehi to start the process.

"Mr. Salehi, begin enriching up to 20 percent," Ahmadinejad said, adding that Iran is still "open to negotiations on the issue."

Thousands of cancer patients in Iran are in urgent need of the life-saving isotopes which the enriched Uranium would help produce. The domestic production of tritium at an aging Tehran reactor would dry up very soon, leaving thousands of cancer patients to die, the matter which created urgency in Tehran's political leadership, placing the government between allowing the death of thousands of terminally ill Iranian nationals and disregarding international pressure to enrich the required uranium.

The Tehran research reactor, which produces 20 different kinds of medical radio-isotopes for cancer patients, runs on uranium that is some 20 percent U-235 - an enrichment level higher than what is currently produced at Iran's Natanz enrichment facility. The 20% threshold would run the reactor, but Western countries and the IAEA fear it would also bring Iran closer to military nuclear technology.

Iran has requested the International Atomic Energy Agency to arrange for supplying of the fuel to the country. The West has been pressuring Iran to accept a UN-backed draft deal which requires Iran to send most of its domestically-produced low enriched uranium (LEU) abroad for conversion into the more refined fuel that the Tehran reactor needs to produce medical isotopes. The flaw with the proposal is that it would not be implemented for a year, whereas the Tehran reactor would run out of fuel in a few months.

Iranian Foreign Minister Manouchehr Mottaki was optimistic that an agreement on the nuclear fuel proposal would be reached with the Western side if the Tehran demands are met.

US War Secretary Robert Gates, however, ignored Mottaki's remarks, insisting that new sanctions be imposed.