Iran increases uranium stockpile, U.N. agency says

Iran increased its stockpile of low-enriched uranium in recent months despite intense international pressure and claims that a computer virus had slowed its program, a report Friday by the U.N.’s nuclear watchdog agency indicates.

At the beginning of February, according to the report prepared for the board of governors of the International Atomic Energy Agency, Iran had nearly 8,000 pounds of uranium enriched to 3.5%, a quantity sufficient for about three nuclear weapons if further enriched to 90%.

The U.S. and its allies suspect Iran of seeking to develop atomic weapons; Iran contends that its program is for peaceful purposes only.

The production rate of low-enriched uranium has remained unchanged, the report reveals. However, analysts pointed out that the number of centrifuges said to be producing it has increased. That raised the possibility, according to David Albright of the Institute for Science and International Security, of ongoing production problems or continuing after-effects of the computer virus.

Many computer experts believe that the Stuxnet computer program was created by Israel or the United States as part of a covert effort to hamper what they believe is Iran’s drive for an atomic weapon. The U.S. and Israel have recently lengthened the amount of time they estimate it would take Iran to build a nuclear weapon.

The IAEA also said it had received new information about possible military dimensions to the Iranian nuclear program, but the report went into few details.

In a restricted copy of the document obtained by The Times, IAEA Director-General Yukiya Amano highlighted concerns about possible “past or current undisclosed nuclear-related activities related to the development of a nuclear payload for a missile.” Agency officials criticized Iran for failing to cooperate on the issue.

Earlier IAEA reports have noted that such activity may have continued even after 2004, a year that was previously believed to have marked the end of a possible military dimension to Iran’s work.

“The IAEA’s latest report on Iran again demonstrates that Iran is not just refusing to comply with its international nuclear obligations, but Iran continues its effort to expand its nuclear program and move closer to a nuclear weapons capability,” White House spokesman Tommy Vietor said.

Vietor said Washington would continue increasing pressure on the Islamic Republic to meet its international obligations.

Damianova is a special correspondent.

Times staff writer Ken Dilanian in Washington contributed to this report.