Britain, France and Germany challenged Iran's answers to questions about its nuclear programme accepted by the UN atomic watchdog and said Tehran would pay a price for further evasiveness and defiance.
Iran countered at an International Atomic Energy Agency governors meeting in Vienna that a recent IAEA report exonerated it of suspicions that it secretly sought to build atom bombs.
The Islamic Republic's IAEA ambassador said further UN Security Council sanctions adopted on Monday would have no effect on Iran's "exclusively peaceful nuclear activities".
But most on the 35-nation IAEA body, while recognising Iran had provided information to ease some concerns about past activity, said Tehran had much more to do to clean its slate, including addressing what inspectors call serious intelligence indicating that it studied how to "weaponise" nuclear materials.
Iran says its uranium enrichment programme is meant only to generate electricity. But its history of nuclear secrecy and curbs on IAEA inspections stoke fears it could turn to producing nuclear arms. IAEA Director Mohamed ElBaradei told the governors on Monday his inspectors had clarified all but one remaining issue of nuclear proliferation concern in Iran.
The rest were "no longer outstanding" and this was "obviously encouraging". But Britain, France and Germany, who sponsored a third, tougher set of Security Council sanctions on Iran, adopted on Monday, cast Iran's recent actions in a more negative light.
"Over a wide range of issues on which the agency asked for clarification, the answers are less than satisfactory," they said in a speech given by British IAEA Ambassador Simon Smith.
"In conclusion, (ElBaradei's) report leaves our three countries in no doubt that Iran's record in complying with these requirements remains abysmal," he said, referring to Security Council demands for a halt to nuclear work and full transparency about its programme.