The UN atomic watchdog today criticised Iran for failing to comply with nuclear safeguards.
The International Atomic Energy Agency (IAEA) report fell short of passing a damning resolution - as the United States had hoped - but Washington quickly seized upon it as an opportunity to apply further pressure Muslim state.
After a two-day debate, the IAEA's governors criticised Iran's failure to comply with agreements designed to prevent the use of civilian nuclear resources to make atomic weapons.
"The board shared the concern expressed by [IAEA chief] Mohamed El Baradei in his report at the number of Iran's past failures to report material, facilities and activities as required by its safeguards obligations," the IAEA said.
The board urged Iran to remain "transparent" and accept without delay or conditions more intrusive, short-notice inspections to dispel US suspicions Iran is using its nuclear power programme as a cover to develop atomic weapons.
The board also urged Iran not to introduce uranium to its enrichment facilities at Natanz, which has centrifuges that experts believe could produce weapons-grade material.
US President George W. Bush, who has accused Iran of planning to make nuclear weapons - a charge Tehran denies - welcomed the IAEA statement.
"Iran needs to comply. Otherwise the world will conclude that Iran may be producing nuclear weapons," White House spokesman Mr Ari Fleischer told reporters.
"It is international reinforcement of the president's message yesterday that the world, broadly speaking, joins together in fighting proliferation and making certain that Iran does not develop nuclear weapons," he continued.
The United States wanted the IAEA to condemn Iran's failings in the strongest possible terms and warn Tehran that it would never allow it to build nuclear weapons.
Diplomats said the United States had wanted a resolution - the strongest type of statement by the board - condemning Iran's failures to comply, but had shelved the idea due to insufficient support.
"The statement by the board was a reprimand, not a condemnation. But it was more than I expected," one diplomat said.
Iran's envoy to the IAEA, Mr Ali Salehi, told reporters: "We are happy that the board did not go with the pressure to come up with a resolution."
Mr Salehi said Iran and 14 IAEA board members belonging to the Non-Aligned Movement (NAM) did not agree with the call for unconditional acceptance of stricter IAEA inspections.
Tehran has made clear it will only sign the Additional Protocol introducing such inspections if a ban on the import of civilian Western nuclear technology is lifted.