TEHRAN, Iran -- Iran has moved some of its centrifuges to an underground uranium enrichment site that offers better protection from possible airstrikes, the country's vice president said Monday.
Engineers are "hard at work" preparing the facility in Fordo, which is carved into a mountain to protect it against possible attacks, to house the centrifuges, Fereidoun Abbasi was quoted as saying by state TV.
Abbasi, who is also Iran's nuclear chief, did not say how many centrifuges have been moved to Fordo nor whether the machines installed are the new, more efficient centrifuges Iran has promised or the old IR-1 types.
He did specify that the centrifuges will be taken to Fordo from Iran's main uranium enrichment facility in Natanz, central Iran.
Uranium enrichment lies at the heart of Iran's dispute with the West, a technology that can be used to produce nuclear fuel or materials for atomic bombs.
The United States and some of its allies accuse Iran of using its civilian nuclear program as a cover to develop atomic weapons. Iran has denied the charges, saying its nuclear program is peaceful and aimed at generating electricity, not nuclear weapons.
Iran has been enriching uranium to less than 5 percent for years, but it began to further enrich its uranium stockpile to nearly 20 percent as of February 2010, saying it needs the higher grade material to produce fuel for a Tehran reactor that makes medical radioisotopes needed for cancer patients.
Iran's higher-grade enrichment efforts are of particular concern to the West because uranium at 20 percent enrichment can be converted into fissile material for a nuclear warhead much more quickly than that at 3.5 percent.
Abbasi said Tehran was in no rush to install the centrifuges and that experts are observing all technical standards.
In June, Abbasi said Iran plans to triple its output of the 20 percent enriched uranium and move the entire program to the new, secretly-built Fordo facility, just north of the holy city of Qom in central Iran.
The bunker facility is to house approximately 3,000 centrifuges. Preparations have been well under way for months now, with electrical wiring, pipe work and other preliminary installations completed in recent weeks.
The West argues that it revealed the existence of Fordo for the first time Sept. 25, 2009 at the G-20 meeting in Pittsburgh but Iran says it did nothing wrong and that it informed the U.N. nuclear watchdog agency, the International Atomic Energy Agency, in a Sept. 21 letter, at least two years before the plant would be operational.