Iranian President Hassan Rouhani addresses the General Debate of the 74th session of the UN General Assembly at the UN headquarters in New York, on Sept. 25, 2019. Rouhani on Wednesday ruled out negotiations with the United States unless the latter lifts sanctions on his country first. (Photo: Xinhua)

Iran accused European nations of hypocrisy on Tuesday for criticizing its latest step back from a nuclear deal while failing to fulfill their commitments of relief from US sanctions.

President Hassan Rouhani made no mention of a new report from the UN nuclear agency that reveals its inspectors detected uranium particles of man-made origin at an undeclared site in Iran.

But Iran's envoy to the International Atomic Energy Agency in Vienna said the UN watchdog had been given access to the site "with the utmost cooperation and clarification."

"Cooperation between Iran and the agency on this issue is still ongoing. Therefore, any attempt to prejudge and present immature assessment of the situation would be aimed at distorting the facts for political gains," Gharib Abadi said in a statement.

Britain, France, Germany and the EU have been trying to salvage the 2015 Iran nuclear deal since the US unilaterally withdrew from it in May 2018 and began reimposing sanctions.

A year after the US pullout from the Joint Comprehensive Plan of Action (JCPOA), Iran began reducing its commitments to the deal hoping to win concessions from those still party to the accord.

Iran's latest measure came last week, when engineers began feeding uranium hexafluoride gas into mothballed enrichment centrifuges at the underground Fordow plant south of Tehran.

On Monday Britain, France, Germany and the EU said Iran's decision to restart activities at Fordow was "inconsistent" with a 2015 nuclear deal.

"The E3/EU have fully upheld their JCPOA commitments, including sanctions-lifting as foreseen under the JCPOA," they said. "It is now critical that Iran upholds its JCPOA commitments and works with all JCPOA participants to de-escalate tensions."

Iran's Foreign Minister Mohammad Javad Zarif hit back on Tuesday. 

"'Fully upheld commitments under JCPOA' YOU? Really?" he tweeted.

Zarif said Iran had already "triggered and exhausted" a dispute resolution mechanism in the troubled accord.

German Foreign Minister Heiko Mass on Monday threatened the use of "all the mechanisms laid down in the agreement" to make Iran comply with its obligations under the JCPOA.

On Tuesday, Rouhani said Iran only began scaling back its nuclear commitments a year after the US withdrawal to give the other parties time to make up for it.

"We waited for a year," Rouhani told a televised news conference. "Nobody in the world can blame us by saying, 'Why are you abandoning your commitments under the JCPOA today and why have you launched Fordow today?'"