The assessment was published Monday in a quarterly report by the International Atomic Energy Agency, or IAEA.
The U.N. atomic watchdog is preparing to release its latest report on whether Iran continues to comply with the 2015 deal aimed at keeping Tehran from building nuclear weapons in exchange for incentives.
A first round of American sanctions took effect in August, and the second round on November 4.
According to the report, Iran's stockpiles of low-enriched uranium is within the limits set by the JCPOA.
A senior diplomat with knowledge of the situation said that there is "nothing that indicates that. cooperation from Iran or its attitude has changed since November 5".More news: Style nationalism comes under fire at WWI commemorations in Paris
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Iran sold 700,000 barrels of crude oil to private companies for export in a second round of sales aimed at countering US sanctions on the country's exports, oil ministry news website SHANA reported.
Iran has said the future of the JCPOA would be called into question if it no longer received the economic benefits of the deal.
The U.S.is said to have allowed India to also develop an Iranian port for trade with Afghanistan, without risking secondary sanctions for being involved in business with Tehran.
The Iran nuclear deal was scrapped by US President Donald Trump, who undermined Obama's diplomatic victory and re-imposed sanctions previously lifted under the agreement.
However, some European companies have already pulled out of Iran.