Rafael Grossi
Rafael GrossiReuters

Iran has failed to answer questions about the discovery of uranium particles at former undeclared sites in the country, the head of the International Atomic Energy Agency (IAEA) said Monday, according to The Associated Press.

IAEA chief Rafael Grossi called on Tehran to provide information “without further delay.”

The IAEA recently released a report saying that Iran has failed to explain traces of uranium found at several undeclared sites.

"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)," the report said.

Grossi has been pushing Iran for answers on three sites dating back many years where inspections had revealed traces of uranium of man-made origin, suggesting they were once connected to Iran’s nuclear program.

While the IAEA has not identified the sites in question, one of them is believed to be the Turquzabad facility which was identified by Prime Minister Benjamin Netanyahu during his address before the UN General Assembly in 2018 as a "secret atomic warehouse."

The issue is separate from the negotiations aimed at bringing the United States back into Iran's 2015 nuclear accord with world powers.

Speaking on Monday to the IAEA's board of governors, Grossi said that “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.”

He said Iran also hasn't answered questions regarding another undeclared location.

“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," added Grossi, according to AP.

In addition to the concerns over Iran’s undeclared sites, the IAEA has also reported that Iran’s stockpile of enriched uranium continues to be higher than the limit set by the 2015 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 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."