"The IAEA has not done a purely technical job. It has acted under pressure from certain political circles, especially American," the foreign minister told state television.
"If it had considered matters from a purely technical aspect, it would have closed the file," he said.
Instead, according to Kharazi, the UN nuclear watchdog had "preoccupied itself solely with minor problems by trying to make them bigger and to poison the atmosphere against Iran".
However, the Islamic republic would continue to cooperate, he said.
"We will work within the framework of international obligations," said Kharazi, while stressing that Tehran would "not accept any new obligation".
In Vienna, the UN atomic agency adopted a tough resolution rebuking Iran for failing to come clean about its nuclear programme, which the United States claims is hiding a covert plan to build weapons.
The resolution, written by Britain, France and Germany with help from the United States, was adopted unanimously by the IAEA's 35-nation board of governors.
Iran's representative to the IAEA, Seyed Hossein Mussavian, said the latest resolution was "more positive than previous ones" adopted by the IAEA. "It contains no threat or condemnation," he said.
At the meeting in the Austrian capital, "nobody called for the Iranian file to be sent to the (UN) Security Council (for possible sanctions). That was a very important success," said Mussavian.
It proved that "thanks to Iran's cooperation with the IAEA, the initial worries have been dispelled", he told the television.
The resolution "clearly states only two technical problems remain to be resolved for the file to be closed definitively", he said, referring to traces of enriched uranium in Iran and its planned uses for high-tech centrifuges.