Iran’s supply of low-enriched uranium as of Aug. 21 was 88.4 kilograms or 194.89 pounds, well below a 202.8 kilogram limit. The level of purity did not exceed the limit of 3.67 percent, suitable for civilian power needs but not for weapons. The heavy-water supply totaled 111 tons, below the 130-ton limit.
Under an American law, Mr. Trump is required to assess Iran’s adherence every 90 days, and he has reluctantly found Iran in compliance so far. But Mr. Trump also said he expected to find Iran in violation at the Americans’ next 90-day interval, in October.
Whether such a finding would be the catalyst for Mr. Trump to withdraw from the agreement is unclear. Many of his top aides have advised him to honor the accord.
At the same time, Mr. Trump has increasingly accused Iran of human rights violations and support for terrorism, issues that were not part of the nuclear agreement.
Mr. Trump has also accused Iran of flouting the United Nations Security Council resolution that put the agreement into effect, which calls on Iran not to test ballistic missiles. He has imposed new sanctions on Iran in response, which the Iranians have denounced as a violation of the nuclear agreement.
The Trump administration also appears to be laying the basis to request more aggressive inspections in Iran by the International Atomic Energy Agency, including at highly restricted military sites, arguing that a verification provision of the nuclear accord allows them. Iranian officials appear to have ruled out such requests, calling them “merely a dream.”
The agency’s latest report was issued a week after Mr. Trump’s United Nations ambassador, Nikki R. Haley, met with the nuclear agency’s top officials in Vienna to express American concerns about their ability to verify Iran’s full compliance with the accord.
Ms. Haley made no comment Thursday on the report’s findings. But she issued a statement that suggested that the administration would push the inspections argument further.
“If inspections of Iranian military sites are ‘merely a dream,’ as Iran says, then Iranian compliance with the J.C.P.O.A. is also a dream,” she said.
Political analysts who once thought the accord would probably survive the Trump administration are less optimistic now.
“The Trump administration simply doesn’t like this agreement,” said Cliff Kupchan, chairman of the Eurasia Group, a political risk consultancy in Washington.
“It will continue to look for a way not to certify Iran’s compliance in coming months,” Mr. Kupchan said. “And it will probably seek I.A.E.A. inspection of Iran’s military facilities to an extent Iran deems intolerable. This deal is still in a lot of trouble.”