"Nothing very important has happened," foreign ministry spokesman Hamid Reza Asefi told reporters, trying to play down fresh alarm over an atomic energy programme the United States sees as a cover for weapons development.

The United States and the European Union Saturday called on Iran to go back on its decision to resume the construction of centrifuges, announced by Tehran in retaliation to a critical resolution passed this month at the International Atomic Energy Agency (IAEA).

But Asefi insisted that while Iran would go ahead with making centrifuges as of June 29, it was still sticking to its pledge to suspend enriching uranium.

"We had agreed with the three Europeans to have cooperation with Iran. We said in the Tehran declaration that we would suspend enrichment, and we will stick to this," Asefi said, referring to a deal made last October with Britain, France and Germany.

He said Iran's announcement to resume making parts for centrifuges was merely a response to a failure by the EU "big three" to meet their side of another deal in which they had apparently pledged to help remove the Iran dossier from the top of the International Atomic Energy Agency's (IAEA) agenda.

"We had another agreement... to voluntarily suspend component production, and they agreed to close our case at the IAEA (in June). But they did not meet their obligations," Asefi said.

Diplomats, however, gave a completely different account of what the two sides had agreed upon.

"In February there was an exchange of letters, an agreement for Iran to stop testing and making centrifuge parts, and in return the Europeans said they would help Iran get its dossier off the top of the IAEA agenda," a diplomat explained.

But the diplomat asserted "there were clear conditions" from Britain, France and Germany: IAEA chief Mohamed ElBaradei had to be satisfied by Iran's level of cooperation, and there needed to be no new revelations uncovered by IAEA inspectors.

Before the June meeting of the UN nuclear watchdog, ElBaradei said Iran was not fulfilling its pledge to fully cooperate, while inspectors also uncovered yet more suspect traces of highly-enriched uranium as well as undeclared Iranian activity on advanced P-2 centrifuges.

Despite this, Asefi claimed it was the "Europeans who did not meet their side of the agreement". He even said this was "shocking" for the Islamic republic, blaming familiar arch-enemy the United States.

"The United States is making a psychological war against Iran. We cannot forget that the US went to war againt Iraq because of weapons of mass destruction but has not found any," he said.

"We will not give up our right to peaceful nuclear technology," he added.

Uranium enriched to various degrees is used both for power generation and nuclear weapons. The United States in particular believes Iran is using the first as cover for developing the second, something which Tehran denies.

Iran's suspension of its work on the fuel cycle was part of a package of "confidence-building measures" put in place while the IAEA carried out an extensive probe of its nuclear programme.

And Asefi said that component building would only be carried out under IAEA supervision.

"If we had any different intentions we would not have written a very transparent letter announcing our intention," he insisted.

"Our policy with the IAEA has not changed. What has changed is our obligations to the EU. The coming and going of inspectors is routine and we welcome it," Asefi said.

But he also refused to say if the centrifuge work would also apply to sophisticated P-2 machinery, saying the issue would soon be discussed with the IAEA and the European three.

WAR.WIRE