The IAEA ended a week-long deadlock Saturday by adopting a US-backed resolution condemning Iran for hiding nuclear activities.
"A resolution is being imposed, and I think I am using the expression with true definition of the word, on the (International Atomic Energy Agency) board by a single country," senior foreign ministry official Amir Zamaninia told an IAEA meeting in Vienna, according to a copy of his speech made available to reporters.
A senior Western diplomat said the compromise text worked out after non-aligned states sought to soften the resolution was "still an important signal for the Iranians to continue and intensify cooperation" with the IAEA>
But Zamaninia said the resolution was "a setback, a serious setback" as it portrayed "a rather benign progressive situation as a condition of high alert."
He said IAEA chief Mohamed ElBaradei has already reported "the positive trend of active cooperation by Iran and also a process of resolving issues that is gaining pace exponentially".
The resolution that was adopted came a day after Iran had put off a UN inspection mission until the end of April in what one diplomat close to the IAEA described as "potentially a large problem in the verification process."
But Iranian ambassador Pirooz Hosseini told AFP Saturday that IAEA inspectors could in fact visit Iran earlier than the end of next month.
Hosseini said his country had put back the inspection mission, scheduled to start this week, "due to the approach of the Iranian New Year" but that if people were back in their offices soon after the holiday, which starts next week, then IAEA inspectors could come.
The IAEA, which verifies the nuclear Non-Proliferation Treaty (NPT), has since February 2003 been working to determine whether Iran's nuclear program is peaceful, or devoted to secretly developing atomic weapons, as the United States has charged.