However, Najafi stressed that the measures do "not mean that right now Iran will start any activities contrary to the JCPOA," adding that Iran had already notified the IAEA of a plan to resume activity at its uranium conversion facility
He went on to say that negotiations were still continuing at an expert level but he pointed out that it could not be an "endless process" and needed to be concluded "very soon."
Restarting nuclear activities means boosting uranium enrichment capacity by producing new centrifuges, according to the head of the Iranian Atomic Energy Organization, Ali Akbar Salehi.
As the Iranian nuclear chief specified later in the day, a facility to build advanced centrifuges would be completed next month.
READ MORE: US Policy on Iran Poses 'Additional Risks in Region' — French FM
Commenting on Trump's move Iranian President Rouhani said that Tehran was not going to withdraw from the JCPOA, and that the agreement remains between Iran and the remaining signatories to the deal. He noted that, unlike Iran, the United States had never fulfilled its obligations under the nuclear deal.
On July 14, 2015, the European Union and the P5+1 group of countries — China, Germany, France, Russia, the United Kingdom and the United States — signed the Joint Comprehensive Plan of Action (JCPOA), also known as the Iranian nuclear deal, with Tehran.