Earlier on Monday, China - a signatory to the JCPOA along with France, Germany, Britain and Russian Federation - called on the United States to "give up its wrong approach such as unilateral sanctions and extreme pressure against Iran".
Inspectors from the United Nations nuclear watchdog have verified that smaller numbers of various advanced centrifuges had been or were being installed, the spokesman added.
Iran is moving towards enriching uranium by installing more advanced centrifuges in breach of the 2015 nuclear deal with world powers, the International Atomic Energy Agency said on Monday.
But since Iran has not yet given any to the IAEA it is hard to verify the particles' origin, and it is also not clear whether the traces are remnants of material or activities that predate the landmark 2015 deal or more recent, the diplomats say.
The prepared opening statement from the IAEA chief to the board appeared to acknowledge the ongoing failure by Iran to explain the traces of uranium detected at the Tehran facility.
In his remarks, Mr Feruta, who was named Acting Director General following the death of Director General Yukiya Amano in July, provided an update on developments in various areas of the Agency's work since the last regular Board meeting three months ago.
But Tehran has refused to re-open negotiations with the USA, and has instead pushed the other parties to the 2015 agreement, mainly Europe, to find a way to allow Iran to keep selling its crude oil overseas - essentially to evade the US sanctions.
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He added that Iran had also informed the agency it would modify lines of research centrifuges so that enriched uranium was produced, which is not allowed under the deal.
Israeli intelligence agents translated the files and provided the information to world powers in order to enlighten and warn them about the violations of the nuclear deal that Iran had been carrying out, along with the highly advanced nuclear technology that had already taken place prior to the JCPOA negotiations that Iran had lied about in the first place.
He said he emphasized to Iranian authorities "the importance of full and timely cooperation by Iran".
Iran was infuriated by the Trump administration's unilateral decision to walk away from the deal signed by former President Barack Obama and the subsequent "maximum pressure" campaign of sanctions imposed by Mr. Trump.
Despite Washington's withdrawal from the deal in May 2018, Tehran remained fully compliant with the JCPOA for an entire year as confirmed by the IAEA in several reports, waiting for the co-signatories to fulfill their end of the bargain by offsetting the impacts of Washington's sanctions on the Iranian economy.
Under the JCPOA Iran is only meant to enrich uranium using the less advanced IR-1 centrifuge model.
The Elysee Palace in Paris said Macron and Putin agreed "all concerned parties" should act to "ease tensions".