Iranian cooperation with the United Nations' atomic watchdog will only continue if US "plots" to refer compliance concerns the UN Security Council continue.
President Mohammad Khatami said Washington, which accuses Iran of building a secret atomic arms programme, had "tried its utmost" at last week's meeting of the International Atomic Energy Agency (IAEA) to send Iran's nuclear case to the Council for possible sanctions.
"We will continue our cooperation with the agency as long as we know the US plots are not effective," Mr Khatami told reporters after a cabinet meeting.
Tehran was enraged by the IAEA resolution approved on Saturday which stopped short of reporting Iran to the Council but "deplores" its failure to declare sensitive nuclear technology which could be used to make bomb-grade uranium.
In response, Iran cancelled a planned visit of IAEA inspectors scheduled for Friday. It relented on Tuesday and said inspectors could return on March 27th.
Mr Khatami said Tehran expected the IAEA to take Iran's case off the top of its agenda and to allow it to continue to develop nuclear technology for peaceful purposes.
"We are not pessimistic about this but success depends on the US attempts and our costly efforts, which of course we will continue," he said.
Iran says it wants to use its atomic programme to generate electricity.