The UN's International Atomic Energy Agency (IAEA) says Iran is keeping its stocks of uranium and heavy water within the limits set by the nuclear deal it reached with world powers last year.
The agency said in a report released on May 27 that during the last three months "Iran had no more than 130 metric tons of heavy water [and] Iran's total [low] enriched uranium stockpile did not exceed 300 kg."
The assessment shows Tehran is complying more closely with its limits than it did at the time of the agency's previous quarterly report.
In its last report in February, the IAEA said Iran had briefly overstepped the limit for its heavy-water stock, but then came quickly back within the bounds of the deal.
Heavy water is a potential proliferation concern because it is used in reactors that produce substantial amounts of plutonium, a potential path to nuclear weapons.
The IAEA is responsible for monitoring the agreement Iran signed in July with the United States, Russia, China, Britain, France, and Germany that reduces and limits Tehran's nuclear activities in exchange for sanctions relief.