WASHINGTON — The United Nations’ nuclear watchdog said Thursday it suspects that Iran might be trying to develop a nuclear warhead that could be placed atop a missile, its sharpest challenge to date of Iran’s claims to be pursuing an exclusively peaceful nuclear program.
The report by the International Atomic Energy Agency conflicts with a 2007 U.S. intelligence community assessment that Iran halted its nuclear weapons program in the fall of 2003. It is more in line with reported European and Israeli estimates that Iran, along with enriching uranium that could fuel a nuclear bomb, is experimenting with constructing a warhead.
The Vienna-based IAEA said it had collected “broadly consistent and credible information” from “a variety of sources” about Iran’s military-related nuclear activities.
“Altogether, this raises concerns about the possible existence in Iran of past or current undisclosed activities related to the development of a nuclear payload for a missile,” it said.
Senior Obama administration officials called the report disturbing, and they said the U.S. assessment of Iran’s nuclear ambitions is under review as part of a new National Intelligence Estimate. The officials briefed reporters on condition of anonymity under White House-imposed ground rules.
The IAEA report also confirms that Iran, as it claimed last week, has begun enriching uranium to a purity of nearly 20 percent, closer to what’s needed for nuclear bomb fuel.
A U.S. official, however, said Iran is producing an estimated 100 grams per day of the 20 percent pure uranium — at a rate that would take it five to seven years to have enough for a bomb if it were enriched further. Weapons-grade uranium is roughly 90 percent pure.
Perhaps more worrisome, the IAEA said Iran has moved most of its current stock of low-enriched uranium to a pilot enrichment plant, indicating it is planning to convert it to the more pure form.
The steps Iran is suspected of taking toward a nuclear warhead have been cited in previous IAEA and media reports.
The agency’s overall conclusions, however, suggest a hardening stance from the IAEA in dealing with Iran.
The report also seems likely to affect high-stakes diplomacy over new sanctions on Iran.
U.S. officials and private analysts cautioned that the document also shows that Iran is continuing to encounter technical difficulties in its nuclear program. It has 3,772 centrifuges running at its plant in Natanz, the IAEA said, fewer than in November. That could indicate Iran hasn’t overcome problems with its centrifuges, rapidly spinning machines that enrich uranium.
