Vienna International Centre, where IAEA offices are located
Vienna International Centre, where IAEA offices are locatediStock

Iran has failed to explain traces of uranium found at several undeclared sites, according to a new report by the UN nuclear watchdog showed which was obtained by Reuters on Monday.

"After many months, Iran has not provided the necessary explanation for the presence of the nuclear material particles at any of the three locations where the Agency has conducted complementary accesses (inspections)," says the report by International Atomic Energy Agency (IAEA) chief Rafael Grossi to member states.

"The Director General is concerned that the technical discussions between the Agency and Iran have not yielded the expected results," the report added.

"The lack of progress in clarifying the Agency's questions concerning the correctness and completeness of Iran's safeguards declarations seriously affects the ability of the Agency to provide assurance of the peaceful nature of Iran's nuclear program," it said.

The report comes three months after Britain, France and Germany scrapped a US-backed plan for the IAEA’s 35-nation Board of Governors to criticize Iran for failing to fully explain the origin of the particles.

Reuters noted that it will now be up to the three European powers to decide whether to revive their push for a resolution criticizing Iran.

In a separate quarterly report also sent to member states on Monday and seen by Reuters, the IAEA said that Iran's quarterly increase in its stock of enriched uranium was the lowest since August 2019 at just 273 kg, bringing the total to 3,241 kg.

That total is many times the 202.8 kg limit set by the nuclear deal, but still well below the more than six tons Iran possessed before the deal.

Iran has consistently scaled back its compliance with the 2015 nuclear deal with world powers in response to former US President Donald Trump’s withdrawal from it in May of 2018.

It has continued to do so even as the US under President Joe Biden began indirect talks with Iran on a return to compliance with the agreement.

The talks in Vienna have involved diplomats from Britain, China, France, Germany, Iran and Russia who met the Iranian representatives, while US diplomats participated indirectly in the talks from a nearby hotel.

The US and European Union both said recently that more work was needed to revive the 2015 deal, while Iranian President Hassan Rouhani said the "negotiations have achieved 60-70 percent progress."