Iran remains in compliance with the 2015 nuclear accord signed with six world powers, the United Nations atomic watchdog says.
In its confidential quarterly report seen by U.S. media on February 22, the International Atomic Energy Agency (IAEA) indicated that Tehran was meeting the accord's key requirements.
The report comes four months ahead of a deadline set by President Donald Trump for Congress and European allies to fix what he called "disastrous flaws" in the deal or face a U.S. withdrawal from the deal.
Trump and other U.S. officials claim Tehran is violating the "spirit" of the deal and that it is using its ballistic-missile program to circumvent nuclear restrictions.
Iran denies the allegations, insisting it is adhering to the accord and that its nuclear program is strictly for power-generation purposes.
Trump has also expressed concerns that some terms of the deal, signed under his predecessor, will expire in 2026.
The deal, signed by Iran with the United States, Britain, France, Germany, China, and Russia, put limits on Iran's nuclear program in return for the easing of economic sanctions against the country.
The IAEA reports have consistently shown Iran adhering to the deal in the two years since it took effect.
Naval Propulsion Plan
According to the latest report, the number of centrifuges to enrich uranium, Iran's total stockpile of low-enriched uranium, and the volume of heavy water -- a reactor coolant -- have all remained below the agreed maximum.
Lowly enriched uranium can be used for peaceful applications such as power generation, Iran's stated aim, but also for a nuclear weapon if processed to a higher level.
The report also said that Iran had told the IAEA by letter of a decision that "has been taken to construct naval nuclear propulsion in future."
The UN atomic watchdog requested "further clarifications and amplifications," the report said, adding that, if a decision had been reached to build new facilities for naval nuclear propulsion, it needed to supply initial design information.
Tehran had yet to respond, according to the report.
Iran insists its nuclear program is only for peaceful purposes, while the United States and other countries claim it has been trying to develop nuclear weapons.