Iran has started using advanced centrifuges to enrich uranium, the UN's nuclear watchdog says, in a further breach of its 2015 nuclear deal with world powers.
Advanced centrifuges "were accumulating, or had been prepared to accumulate, enriched uranium," the Vienna-based International Atomic Energy Agency (IAEA) said in the report to member states cited by Western news agencies on September 26.
In addition, IAEA inspectors have verified that Iran has pushed ahead with preparations to install more advanced centrifuges that can refine uranium more efficiently.
Under the 2015 nuclear agreement that puts curbs on Iran's nuclear program in exchange for an easing of sanctions, Tehran is only meant to enrich uranium using less efficient centrifuges.
The accord has been in jeopardy since May last year when the United States withdrew from it and reimposed sanctions on Iran, targeting its oil exports and crippling its economy.
In response, Tehran has reduced some of its commitments under the nuclear accord over the past few months.
The deal's European signatories -- Britain, China, France -- have tried to salvage the accord, but Iran has repeatedly accused them of not doing enough to protect it from the effects of U.S. sanctions.
U.S. President Donald Trump wants to force Iran to renegotiate the 2015 nuclear accord, arguing that the terms were not tough enough to prevent the country from developing nuclear weapons, and agree curbs to its ballistic-missile program.
Iran has refused, insisting its nuclear program was strictly for civilian energy purposes and that its missile capabilities were not negotiable.
Speaking on September 26 on the sidelines of the UN General Assembly in New York, Iranian President Hassan Rohani said Iran's steps to scale back its nuclear commitments are reversible if the European parties to the nuclear agreement carried out their promises to salvage the pact.
He also urged Washington to "cease this policy of maximum pressure" in favor of "dialogue, logic, and reason," a day after the U.S. administration stepped up pressure on Tehran, authorizing the State Department to bar senior Iranian officials and family members from entering the United States as immigrants or nonimmigrants.
Rohani said the move had no impact as "Iranian officials have no desire to travel to America.”
“We only come here for the UN events," he added.