In open defiance of the United Nations, Iran is steadily expanding its efforts to enrich uranium, the International Atomic Energy Agency reported Thursday.
In response, the Bush administration immediately pressed for more severe sanctions against the country, at a moment of greatly increased tensions between Washington and Tehran.
In a mild surprise to outside experts, the nuclear agency reported that Iran was now operating or about to switch on roughly 1,000 centrifuges, the high-speed devices that enrich uranium, at its nuclear facility at Natanz.
"They are very serious," said David Albright, a former inspector who is now president of the Institute for Science and International Security, a private nuclear study group. "They are installing faster than was commonly expected."
Coming on the heels of the Bush administration's accusations that Iran's Quds force, an elite covert branch of Iran's military, is sending deadly bombs and other weapons into Iraq, the report heightens what has become a growing confrontation.
Since the last IAEA assessment of Iran's progress, President Bush has ordered a second aircraft carrier group into waters within striking distance of Iran, an unsubtle reminder that, if diplomacy fails, Bush could order a strike on Iran's nuclear facilities. But senior administration officials have insisted in recent days that the show of military force is intended only to remind Iran of Washington's options, and they have dismissed the idea that Bush is considering any attack.
On Thursday, administration officials said they hoping to use the IAEA's conclusions to return to the Security Council for approval of deeper sanctions, and they said the United States would work outside of the Security Council to persuade banks around the world to cut off more lending and export credits to Iran, in hopes of further damaging its oil infrastructure. Undersecretary of State R. Nicholas Burns will travel to London on Monday to begin that process, meeting with the permanent five members of the Security Council and Germany to talk about tougher sanctions.
While Russia and China agreed to the December resolution, which required the inspectors to report back on Iran's compliance within 60 days, they indicated at the time that they were unwilling to escalate the penalties.
The report appeared to confirm that the Iranian government is somewhat behind schedule in its nuclear ambitions: it boasted a year ago of plans to have roughly 3,000 centrifuges up and running by about now. But the 1,000 that it has nearly ready to run is still more than most outside experts believed it had available. If the country could operate 3,000 centrifuges continuously for a year, it could produce about one weapon's worth of highly enriched uranium.