Eight months after celebrating a diplomatic breakthrough designed to address concerns about Iran's nuclear program once and for all, Iranian officials are bracing for a fresh rebuke from the U.N.'s nuclear monitoring agency.

The board of governors of the 35-nation International Atomic Energy Agency convenes for a three-day meeting in Vienna on Monday, and the U.N. body is likely to officially "deplore" Iran's erratic cooperation with IAEA inspectors, who will continue exploring the country's atomic infrastructure for months, according to diplomats and Iranian officials.

The resolution would echo a March warning by the same board and a resolution last week by the Group of Eight leaders who met in the United States. The sting of the language is all the sharper because it is being pushed by three leading European nations that last October coaxed Iran to unveil its clandestine nuclear program.

"We now see the Europeans and the Americans have come together against us," Ali Akbar Hashemi Rafsanjani, a former president and now a senior government official, said at Friday prayers at the University of Tehran, the weekly showcase for hard-line doctrine in this theocracy.

The air of official complaint was palpable in the Iranian capital this weekend, after state-run media heightened expectations that the IAEA would issue Iran the clean bill of health that its leaders insist it deserves. Despite 18 years of secrecy and the country's vast oil and gas reserves, senior Iranian officials declare that the country's nuclear program is intended to produce only electricity, not weapons.

"We are against using it for military purposes," Rafsanjani said, warning that "if they are going to put pressure on us, everybody knows his duty."

The issue shows no sign of going away. U.S. officials, who insist Iran is pursuing atomic weapons, have been pleased that IAEA inspectors have emerged from Iranian nuclear facilities with new questions about Tehran's intentions. The inspectors' latest report noted that Iran had failed to disclose the purchase of magnets needed to enrich uranium and that Iran insists on preparing feed stock for centrifuges, despite its October vow to suspend enrichment activities as a "confidence-building" measure. The IAEA also continues to investigate the radioactive contamination of centrifuges.

Diplomats added that they are concerned by Iran's announced intention to build a heavy-water reactor to produce isotopes for benign applications that could also be produced by a light-water reactor. The heavy-water version would also be able to produce plutonium, used in bombs.

The continuing controversy is testing Iran's pledge to adhere to the October agreement that opened its nuclear program to inspection in the first place.

Each additional disclosure has irritated Iranian opponents of the agreement. Senior conservatives have publicly suggested following the example of North Korea, which last year withdrew from the nuclear Non-Proliferation Treaty (NPT) after its weapons program was discovered.

"If IAEA gives in to U.S. pressure, we will react strongly to defend Iran's national interest," said Mahdi Kouchakzadeh, one of several members of Iran's Revolutionary Guards elected to parliament in February, after conservative overseers disqualified about 2,400 reformist candidates, thereby ensuring conservative control.

"As a lawmaker, I think Iran has to stop cooperation with IAEA and seriously consider withdrawing from NPT," he said in remarks quoted by the Associated Press.

"Pinpricks are hardening the core," said one foreign diplomat resident in Iran. "The way they're circling the wagons, they obviously have something they're protecting there."

The suspicions intensified after the February discovery that Iran had failed to disclose it was assembling P2 gas centrifuges, which would enrich uranium far more efficiently than the model cited in the "comprehensive" declaration it submitted in December. After documenting other apparent deceptions and contradictory explanations, inspectors were delayed for weeks from entering workshops operated by Iraq's Defense Industries Organization.

Diplomats here now say they expect that Iran's file at the IAEA board will remain open until at least November and likely into early 2005. Absent information that conclusively reveals a weapons program, Iran might avoid a referral to the U.N. Security Council, which the Bush administration wants to impose sanctions. But the extended process might aggravate frictions among Iran's ruling elite.

"There's a lot of anger around, based on their unreasonable expectation they would get the issue put behind them in June," said another resident diplomat.

"I don't think they'll cut off their links to the EU-3," the diplomat said, referring to France, Britain and Germany. "There is an element of risk in putting forward an honest resolution."

A senior Iranian official, who asked not to be quoted by name because of the sensitivity of the matter, suggested that the government was unlikely to leave itself without a negotiating partner. "I personally believe this ultimately is going to be managed somehow between the Europeans and the Iranians," the official said.

Former president Ali Akbar Hashemi Rafsanjani asserts that Iran is against using its long-secret nuclear program for military purposes.