Iran assured the world again on Sunday that it had no immediate plans to resume uranium enrichment, a process that can be used to make nuclear weapons but said it might resume making parts for the enrichment equipment.

Angered by a tough U.N. resolution criticizing it for less than full cooperation with the International Atomic Energy Agency, Iran has threatened to reconsider its commitment to the suspension of enrichment activities.

But, in a calibrated response that diplomats believe aims to send a tough message without sparking a major crisis, Iran said it may merely suspend its pledge to stop building uranium centrifuge parts -- a commitment to which Tehran had not fully complied anyway.

Foreign Ministry spokesman Hamid Reza Asefi, echoing comments made Saturday by Iran's top nuclear negotiator, Hassan Rohani, said that Iran would continue to refrain from injecting uranium hexafluoride gas into centrifuges that spin at high speed to produce enriched uranium.

"Right now, there is no discussion about resuming enrichment at all," Asefi said at a weekly news conference.

Iran says its nuclear program is geared solely to producing electricity. Low enriched uranium can be used as fuel for nuclear reactors, but highly enriched uranium can be used to make nuclear weapons.

Iran agreed to suspend enrichment last October to restore international confidence following revelations that it had kept secret sensitive nuclear research for nearly two decades.

The suspension, brokered in talks with Britain, Germany and France, was extended in February to cover the manufacture and assembly of enrichment centrifuge parts.

Iran said the European nations had, in return, pledged to back Iran at last week's IAEA meeting in Vienna.