Iran reports new strides at uranium enrichment plant

US, allies likely to press for another round of sanctions

TEHRAN - Iran has increased the number of operating centrifuges at its uranium enrichment plant to 4,000, a top official said yesterday, pushing ahead with the nuclear program despite threats of new UN sanctions.

The number was up from the 3,000 centrifuges that Iran announced in November that it was operating at its plant in the central city of Natanz. Still, it is well below the 6,000 it said last year it would operate by summer 2008, suggesting the program may be behind schedule.

Deputy Foreign Minister Ali Reza Sheikh Attar, who visited Natanz last week, said yesterday that Iran was preparing to install even more centrifuges, though he did not offer a timetable. "Right now, nearly 4,000 centrifuges are operating at Natanz," Attar told the state news agency IRNA. "Currently, 3,000 other centrifuges are being installed."

The UN has already imposed three rounds of sanctions on Iran for its refusal to freeze its enrichment program, which can be used to produce either fuel for a nuclear reactor or the material needed for a nuclear warhead. In the process, uranium gas is spun in a series of centrifuges known as "cascades" to purify it. Lower levels of enrichment produce reactor fuel - which Iran says is the sole purpose of the program - but higher grades can build a weapon.

The United States and its allies are likely to press the UN later this year for a new round of sanctions after Iran did not accept a package of economic and technological incentives in return for suspending enrichment. But they could face strong resistance from Russia after this month's crisis in Georgia deeply damaged ties between Washington and Moscow.

The United States accuses Iran of seeking to build a nuclear weapon, a claim Iran denies.

Tehran insists it has the right under the Nuclear Nonproliferation Treaty to develop atomic reactor fuel using enrichment.

By reaching 4,000 centrifuges, the program is moving into an industrial-scale program that could churn out enough enriched material for dozens of nuclear weapons. Analysts, however, say Iran would have to change the way the centrifuges are operating to enrich uranium to high, weapons-grade levels, something that would be difficult since the Natanz facility is under IAEA video surveillance.