A defiant Iran rebuffed the head of the International Atomic Energy Agency on Thursday, failing to show up for a meeting to discuss Tehran's plans to move closer to uranium enrichment within days.
Diplomats close to the agency described the move as unusual and suggested it was at least partly triggered by criticism of Tehran by agency head Mohamed ElBaradei during a Wednesday meeting with Iranian envoys.
One of the diplomats said the Iranians appeared taken aback by the firmness of ElBaradei's demands for more cooperation in his agency's investigation of Tehran's nuclear activities. He, like others who spoke to The Associated Press, spoke on condition of anonymity because the meeting was private.
That, and the usually soft-spoken ElBaradei's clear opposition to Iran's plans to resume work with some equipment used in uranium enrichment — a possible pathway to nuclear arms, apparently contributed to Iran's no-show Thursday, he said.
In Washington, Secretary of State Condoleezza Rice signaled Thursday that time was running out for Iran.
"When it's clear that negotiations are exhausted, we have the votes" to take Iran before the Security Council for possible punishment, Rice told reporters in Washington.
Iranian representatives already failed to meet ElBaradei's request Wednesday for clarification of what they describe as plans to restart research on, and development of, uranium enrichment. But Iran promised to do so Thursday.
Iran says it is interested in enrichment to make nuclear fuel, but the United States and an increasing number of other nations say Tehran wants the technology to make weapons-grade uranium for nuclear warheads.
Tehran says it will not actually begin enrichment Monday. But even the restart of equipment testing would be viewed as another move toward fully reviving the program despite Tehran's pledge to fully freeze all its aspects.
"The meeting never took place," said IAEA spokeswoman Melissa Fleming, adding ElBaradei was "still seeking clarification" of what Tehran would do.
But a diplomat accredited to the agency said the IAEA appeared resigned to not getting the details it had asked for before Monday. He cited ElBaradei as saying he did not expect the high-ranking Iranian delegation to ask for a new appointment.
Agency officials said the delegation, led by Mohammad Saeedi, the deputy head of the Atomic Energy Organization of Iran, was en route to Tehran by Thursday afternoon.
With senior Russian officials expected in the Iranian capital at the weekend to discuss nuclear cooperation, Saeedi was unlikely to return before the scheduled restart of work with enrichment equipment.
European powers had hoped that a briefing by IAEA officials would help them determine whether to go ahead with planned talks with Iranian officials in Vienna on Jan. 18 or to cancel them and have Tehran referred to the Security Council.
That path was cleared late last year, when the 35-nation board of the IAEA found Iran in noncompliance of the Nuclear Nonproliferation Treaty for keeping its uranium enrichment program secret for decades and conducting other work that could be used for a nuclear weapons program.
The Europeans, with American backing, then decided to give diplomacy another try in efforts to gain more international support for their stance.
ElBaradei has repeatedly said his agency's nearly three-year probe of Iran's nuclear activities has turned up no conclusive evidence of nuclear weapons activities.
At the same time, he has been increasingly critical of delays and conflicting information provided to his inspectors — who in November reported finding drawings in paperwork provided by the Iranians of what appeared to be parts of nuclear warheads.
Iran's record on enrichment has added to international concern.
Tehran's decision in August to resume uranium conversion — a precursor to enrichment — led the Europeans to break off talks on grounds that the move violated Iran's freeze pledge.
The two sides nonetheless agreed last month to try to bridge differences with the Europeans, hoping that the Iranians would accept a plan that would move their nascent enrichment program to Russia — in theory depriving them of the ability to misuse it for weapons.
But hopes were dimmed by Tehran's steadfast refusal to consider giving up the right to enrich domestically.