The International Atomic Energy Agency (IAEA) is voicing increasing frustration that Iran is failing to provide answers about uranium particles that could shed light on the scope of past nuclear activities.
In its latest quarterly report on Iran, the Vienna-based nuclear agency said it had found additional uranium particles at two locations last year but that Iran has yet to provide explanations.
In addition, officials in Tehran has not provided credible answers on uranium particles found at a third location for the past 18 months.
"The agency is deeply concerned that undeclared nuclear material may have been present at this undeclared location," the IAEA report said.
The IAEA also reported that Iran has now enriched nearly 3 tonnes of uranium.
This is nearly 15 times the amount allowed under Tehran's 2015 deal with major powers, which was designed to prevent the country from amassing enriched uranium that can be further processed into weapons-grade material.
Australian Associated Press