The U.S. Ambassador to the International Atomic Energy Agency says the agency's resolution censuring Iran for cover-ups in its nuclear program reflects deep international concerns about Tehran's nuclear program and shows the need for more inspections.

U.S. envoy, Kenneth Brill, told reporters the 35-member IAEA board stood firm in the face of Iran's threats. "This resolution is strong and firm despite a concerted campaign led by the most senior levels of the Iranian government to try to intimidate individual board members and the board as a whole and also a full-scale campaign by the Iranian government to discredit this agency."

The board of governors adopted the resolution Friday strongly rebuking Iran for poor co-operation with the U.N. nuclear agency.

The text, drawn up by France, Germany and Britain, expressed serious concern about delays in the inspection process, omissions from written declarations and doubts on explanations provided by Tehran concerning its nuclear program, which it says is for peaceful purposes only.

But the resolution gave Iran no deadlines to come clean on its nuclear program as sought by the United States and it does not seek sanctions for noncompliance.

Iran's officials in Vienna denied any cover-up.

IAEA spokeswoman Melissa Fleming, says Tehran must provide prompt access to data, sites and persons so that the agency can complete the verification process. "We've said it can't go on like this for ever and we'd like to see not only steady progress but accelerated progress. But it requires better and more open co-operation on the part of Iran."

The IAEA board of governors will meet again in September to review Iran's nuclear compliance.