Iran has stayed within limits on its nuclear activities imposed by a 2015 deal with world powers but is close to once again breaching a ceiling on its stock of one chemical, a quarterly report by the U.N. atomic watchdog showed on Friday.
The report was the second since the January inauguration of U.S. President Donald Trump, who has called the pact between six powers and Iran "the worst deal ever negotiated" and branded Tehran an enemy in contrast with his predecessor Barack Obama.
Iran 's stock of low-enriched uranium as of May 27 was 79.8 kg (175.5 pounds), well below a 202.8-kg (446-pound) limit, and the level of enrichment did not exceed a 3.67 percent cap, the International Atomic Energy said in a confidential report sent to IAEA member states and seen by Reuters.
"Everything is running smoothly at this point in time," one senior diplomat said, referring to Iranian compliance with the restrictions under the deal.
Obtaining enough highly enriched uranium or plutonium is the biggest hurdle to producing a nuclear weapon. The 2015 deal aimed to extend the time Iran would need to build an atomic bomb, if it chose to, to a year from a few months. Weapons-grade uranium has an enrichment level of around 90 percent.
But Iran 's stock of heavy water, a chemical used as a moderator in a type of nuclear reactor that can produce plutonium, reached 128.2 tons, just below a 130-tonne limit, the IAEA report said. Iran was building one such reactor but it has had its core removed under the deal and is being redesigned.