20% kick off

The move came after Iranian President Mahmoud Ahmadinejad tasked the Atomic Energy Organization of Iran with enriching uranium to 20 percent in order to meet the demands of the country's cancer patients.

Iran had informed the International Atomic Energy Agency (IAEA) previously that it would start enriching uranium to 20 percent on Tuesday in the presence of the inspectors and observers from the agency.

"The enrichment started on Tuesday in a separate cascade from the production line that enriches uranium in Natanz," Iranian Atomic Energy director Ali-Akbar Salehi declared in a television interview.

"We opened a new cascade, called S8, in Natanz which is more on a lab scale," Salehi explained, adding that beginning enrichment, "does not tantamount to the end of interaction and negotiations on a UN-brokered proposal on fuel swap."

"The Islamic Republic of Iran is still ready to continue cooperation if the negotiation parties act wisely and end wasting time," Salehi stressed, indicating that doors are still open for talks with Iran about nuclear fuel swap.

Iran aims to meet its need of 120 kg (264 lb) of 20 percent-enriched uranium to fuel the Tehran research reactor, which produces medical isotopes for cancer patients and is soon to run out of fuel.

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 aging 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.