The resolution deplored the level of Iranian cooperation and called for the International Atomic Energy Agency's (IAEA) 15-month-old investigation into Iran's alleged nuclear weapons activities to be wrapped up within a few months.
The text adopted by consensus at the Vienna-based IAEA's 35-nation board of governors "deplores... that overall . . . Iran's cooperation has not been as full, timely and proactive as it should have been."
The United States, which claims Iran is secretly developing nuclear weapons, said it still wanted Iran's "non-compliance" to be reported to the UN Security Council for possible sanctions, even though Friday's resolution did not call for this.
Iranian Foreign Minister Kamal Kharazi criticised the text -- written by Britain, France and Germany with help from the United States -- but said Iran would meet its commitments to the IAEA.
Iranian President Mohammad Khatami had warned Thursday that the Islamic republic could back away from voluntary commitments such as the suspension of uranium enrichment if the resolution went through.
Iranian foreign ministry official Amir Hossein Zamaninia said in Vienna Friday that the resolution was "a major departure from the reality on the ground," where Iran claims to be cooperating fully.
He said Iran would decide whether to continue voluntary measures according to "the degree of implementation of the reciprocal commitments," a reference to Iran's desire for peaceful nuclear technology transfers in return for carrying out confidence-building measures.
"The resolution really delays the ultimate issue," London-based non-proliferation expert Gary Samore told AFP.
"We still don't know the answer: if Iran is ready to cooperate. The resolution doesn't force the issue. It doesn't include a deadline," he said.
He said it was essential to keep Iran's suspension of enrichment in place, as enrichment is the key for making an atomic bomb.
"I think the Euro-3 (of Britain, France and Germany) have been very clear in private that if the Iranians abandon the October 2003 agreement to suspend enrichment they made with them, then the Europeans are prepared to take the issue to the Security Council," Samore said.
Washington has a harder line and "continues to believe that Iran's documented non-compliance should be reported to the UN Security Council and that its nuclear program presents a threat to international peace and security," said the US ambassador to the IAEA, Kenneth Brill.
But he told reporters that Friday's text was "an important step" and a "very firm consensus resolution on the Iran question."
IAEA director general Mohamed ElBaradei said the "ball remains in Iran's court" to answer questions about contamination of equipment by highly enriched uranium that could be bomb-grade and its work into advanced P-2 centrifuges that can enrich uranium to bomb-grade levels.
The Iranians should take the resolution "as an indication of the interest of the international community for them to clear their name", he said.
"We need to bring this issue to a closure by the end of the year," ElBaradei said, although he said this was not a deadline.
In Washington, State Department spokesman Richard Boucher accused Iran of new attempts to hide sensitive activities, particularly razing nuclear sites at a facility at Lavizan Shiyan (a Tehran suburb).
ElBaradei said "we would like to continue to clarify this new report with Iranian officials."
The IAEA admitted Thursday it had made a mistake in saying in a report in June that Iran had failed to report the import of magnets for P-2 centrifuges, after Iran produced a tape recording of this being told by an Iranian importer to an IAEA inspector.
But the resolution still says that Iran's reporting on the crucial P-2 centrifuge issue has "in some cases ... been incomplete and continues to lack the necessary clarity."