By Zahra Hosseinian and Fredrik Dahl
President Mahmoud Ahmadinejad's announcement was likely to irritate major powers which have offered Iran economic and other incentives to persuade it to suspend enrichment activity that can have both civilian and military uses.
Western officials said after a meeting with Iran's chief nuclear negotiator in Geneva on July 19 it had two weeks to reply to an offer of a halt to new steps towards more U.N. sanctions if Iran froze the expansion of its nuclear programme.
Iran has so far ruled out a freeze to start preliminary talks or suspension of enrichment to start formal negotiations on the incentives package proposed by the six world powers — the United States, Russia, China, Britain, France and Germany.
"Today, we have more than 5,000 active centrifuges," state television quoted Ahmadinejad as saying, adding Western capitals had backed down and now accepted this level of operation.
The U.N. nuclear watchdog, the International Atomic Energy Agency (IAEA), said in May that Tehran had 3,500 centrifuges working at its Natanz facility in central Iran.
The U.N. Security Council has imposed three sets of sanctions in a stand-off that goes back to the revelation in 2002 by an exiled opposition group of the existence of a uranium enrichment facility and heavy water plant in Iran.
Iran, the world's fourth-largest crude producer, says its nuclear activities are aimed solely at generating electricity.
POSITION OF STRENGTH
It says it is ready for negotiations but will not accept any pre-conditions or threats in a row that has helped send oil prices sharply higher, despite falls in the last two weeks.
"Iran does not negotiate with anyone over its obvious nuclear right," Ahmadinejad said in the city of Mashhad.
State radio quoted him as saying the West had retreated in the dispute and had now "accepted that Iran would continue uranium enrichment with its current 6,000 centrifuges".
In a policy shift, a U.S. diplomat attended the Geneva talks and Ahmadinejad said this represented a "success" for Iran.
Iran launched 3,000 centrifuges, a basis for industrial scale enrichment, at Natanz in central Iran in 2007. But they are the 1970s-vintage P1 design, prone to breakdown.
It said in April it had started installing 6,000 new centrifuges at Natanz and testing a more advanced model.
One Iranian analyst said he was surprised by Ahmadinejad's announcement as there had been no indication from the IAEA of such a significant increase of the country's nuclear programme.
Coming just a few weeks after Iran said it test-fired missiles in war games that rattled global financial markets, he said he believed it was part of Iran's diplomatic strategy.
"They want to negotiate from a position of strength," said the analyst, who declined to be named.
Iran says it aims eventually to have 50,000 centrifuges to produce fuel for a planned network of power plants. Enriched uranium can also provide material for arms if refined further.
If running smoothly for long periods, 3,000 would be enough to make material for a warhead in a year, Western experts say.
The United States has warned Iran that it will face more sanctions if it fails to meet the two-week deadline. It has not ruled out military action if diplomacy were to fail.
(Additional reporting by Hashem Kalantari; editing by Mary Gabriel)
