The United Nations' nuclear watchdog says its monitors have detected "natural uranium particles of anthropogenic origin" at an undeclared site in Iran.
The International Atomic Energy Agency (IAEA) does not identify the site in a confidential quarterly report distributed to IAEA member states and seen by Western news agencies on November 11.
Israel has accused Iran of conducting atomic activities at an undeclared site in Turquzabad district on the outskirts of Tehran.
The IAEA report also says Iran's stockpiles of low-enriched uranium are still growing, in violation of the 2015 nuclear deal with world powers, and confirms that the country is now enriching uranium at its Fordow nuclear facility, which is also prohibited by the nuclear agreement.
Iran has every month increased production of enriched uranium to about 100 kilograms, a significant rise from 4 kilograms earlier this year, according to the report.
Tehran has gradually reduced some of its commitments under its nuclear agreement since the United States in May 2018 withdrew from the accord that gave Iran access to world trade in exchange for curbs on its nuclear program, and started reimposing crippling sanctions on the Iranian economy.
Iranian officials complain that the remaining parties to the deal have failed to mitigate the effects of the U.S. sanctions. They have said that all of the steps his country had taken to reduce its commitments to the nuclear pact were "reversible."
Tehran on November 11 said it will continue reducing its nuclear commitments every 60 days, according to Iran's envoy to the UN, Ali Nasimfar.
The EU foreign-policy chief and the foreign ministers of Britain, France, and Germany said they were "extremely concerned" by Iran's decision to resume uranium enrichment at Fordow.
In a joint statement, they said Iran's decision "represents a regrettable acceleration of Iran's disengagement from commitments" under the nuclear deal, and called on Tehran to "return to full implementation of its commitments...without delay."
Iran Appeal To Hard-Liners
Earlier on November 11, Iranian President Hassan Rohani, in a thinly veiled appeal to hard-liners, said staying in the nuclear deal will allow Tehran to restart weapons sales and purchases abroad.
In an address in southwestern Iran, Rohani said that "by continuing the nuclear deal, we will reach a huge political, defensive, and security goal."
"If we save the nuclear deal, Iran's arms embargo will be lifted and we can buy weapons or sell our weapons to the world," he said.
Rohani has been pushing the remaining signatories to the nuclear agreement to fully implement its terms, while hard-liners at home, angry over the U.S. sanctions and their perceptions that Europe has failed to do meaningful business with Iran, have increasingly sought to move away from it.
One of the terms of the deal is that a United Nations-imposed arms embargo on Iran will be lifted in October 2020, which Rohani said is one of the deal’s "significant impacts."
Under its agreement with world powers, Iran also is allowed to operate restricted quantities of first-generation centrifuges.
Trump wants to force Iran to renegotiate the 2015 accord, arguing that the terms were not tough enough to prevent Iran from developing nuclear weapons, and agree curbs to its ballistic-missile program.
Iran has refused, insisting that its nuclear program was strictly for civilian energy purposes.