Iran is honoring the terms of the JCPOA, the International Atomic Energy Agency (IAEA) said in its latest quarterly assessment on Thursday, according to news agencies that obtained the confidential six-page report.
Iran stuck by its nuclear deal with world powers by keeping its uranium stockpile and production capacity below set thresholds, according to the UN inspectors.
"Iran has conducted its enrichment activities in line with its long-term enrichment and R&D enrichment plan” agreed with world powers, according to the six-page restricted document published in Vienna.
Iran "has not pursued the construction of the Arak ... reactor" and has not enriched uranium above low purity levels, it added.
Details of the report are likely to be made public at the next IAEA Board of Governors meeting on September 11-15.
The most recent quarterly report came as a surprise to the US administration which has signaled willingness to declare Iran in breach of the deal.
US President Donald Trump had said in August he did not consider Iran in compliance and dispatched his UN envoy to Vienna to convey his concerns.
However, the IAEA officials said they would not help the Trump administration make a false case for abandoning the agreement.
"If they want to bring down the deal, they will,” an IAEA official told Reuters. "We just don’t want to give them an excuse to.”
Meanwhile, the US State Department has acknowledged the latest IAEA report, the third this year to verify Iran’s compliance with the JCPOA.
The IAEA is responsible for monitoring Iran’s nuclear activities as per the nuclear deal and should also help Iran develop its nuclear energy program.
Iran and the Group 5+1 (also known as E3+3) reached the 159-page nuclear agreement in July 2015 and implemented it in January 2016.
Since the historic deal was signed in Vienna, the IAEA has repeatedly confirmed the Islamic Republic’s compliance with its commitments under the JCPOA.