The UN nuclear watchdog has passed a resolution that paves the way for Iran to be referred to the UN Security Council over its nuclear ambitions.
Iran resumed its controversial uranium conversion work in August
The IAEA did not however set a date for reporting Iran to the council, which could ultimately decide to impose sanctions on the country.
Agency chief Mohammed ElBaradei has said there is still room for diplomacy.
Iran criticised the IAEA for acting without consensus after 12 members abstained from voting on the EU motion.
Iranian security official Javad Vaeidi said the opposition to the resolution meant it had not given a mandate for action against Tehran.
He warned of retaliation, saying "threat invokes threat".
'Failures and breaches'
Mr ElBaradei said the question of referring Iran to the UN Security Council should not come up before November, when the 35-member IAEA board meets again.
He urged all the parties involved to "exploit this window of opportunity" for negotiation and diplomacy.
The US accuses Iran of seeking nuclear arms, a charge it denies. Tehran says it wants the technology purely for peaceful production of energy.
Submitted by Britain, France and Germany, the resolution called on the IAEA board to consider reporting Iran - at an unspecified date - to the UN Security Council.
NUCLEAR FUEL CYCLE
Mined uranium ore is purified and reconstituted into solid form known as yellowcake
Yellowcake is converted into a gas by heating it to about 64C (147F)
Gas is fed through centrifuges, where its isotopes separate and process is repeated until uranium is enriched
Low-level enriched uranium is used for nuclear fuel
Highly enriched uranium can be used in nuclear weapons
As grounds for referral, it states that Tehran's "many failures and breaches" over international nuclear safeguards "constitute non-compliance" with the Nuclear Non-Proliferation Treaty (NPT).
Failure to comply with the NPT is automatic grounds for a report to the Security Council, under IAEA rules.
The IAEA board opted to vote on the resolution rather than adopting it by consensus, its usual approach.
Russia and China, which both strongly opposed the motion, abstained. Venezuela was the only country to vote against it.
India, which had been against the resolution, voted for it.
Indian Prime Minister Manmohan Singh had earlier phoned Iran's President Mahmoud Ahmadinejad to urge him to be prepared to make concessions in order to avoid confrontation, India's foreign ministry said.
The BBC's Frances Harrison in Tehran says Iran is likely to be unhappy that India voted for the resolution, while key allies and trading partners China and Russia merely abstained.
Iran's top nuclear negotiator has already suggested Iran could link future energy deals to which countries supported it at the IAEA, she adds.
The US ambassador to the IAEA, Gregory Shulte, said that now Iran had been found in non-compliance it must be brought before the Security Council, the AFP news agency reports.
Earlier in the week the EU's "big three" dropped a demand that the IAEA should report Iran to the Security Council immediately, apparently because of opposition on the IAEA board.
Iran says its nuclear activities have not violated the NPT.
It has warned that if referred to the Security Council, it could start uranium enrichment - a possible step toward making nuclear arms - and stop allowing unfettered IAEA inspections of its nuclear facilities and programmes.
Iran concealed its nuclear fuel programme for nearly 20 years before it was confirmed by US satellite pictures in 2002. Traces of highly enriched weapons-grade uranium were found at its Natanz plant a year later.
But a recent IAEA report that those uranium traces came from equipment bought several years ago from Pakistan.
Tehran avoided being reported immediately to the Security Council in 2003 by opening talks with Britain, France and Germany.
However, those talks broke down after Iran resumed its uranium conversion process - suspended since November 2004 - in August and pronounced it had an "inalienable right" to produce nuclear fuel.