A recently signed memorandum of understanding between the United States and Iran aims to prevent the Islamic Republic from acquiring a nuclear weapon, but significant uncertainties remain over the whereabouts and status of Iran’s enriched uranium stockpile. The agreement, announced by the White House last week, asserts it will eliminate Tehran’s nuclear ambitions; however, experts and observers question the feasibility of fully verifying and removing the material.
The Trump administration insists that continued nuclear talks in Switzerland will resolve outstanding issues related to “nuclear dust,” a term officials use to describe Iran’s entire supply of enriched uranium. The challenge lies in locating and securing this stockpile, estimated at roughly 440 kilograms of uranium enriched up to 60 percent, a level nearing weapons-grade. Before last year’s military strikes, most of this material was believed to be stored in tunnels beneath the Isfahan nuclear complex, with portions held at the Fordow and Natanz sites.
In June last year, the United States launched over a dozen bunker buster bombs against these three facilities, halting International Atomic Energy Agency (IAEA) inspections in the aftermath. The destruction has complicated efforts to ascertain the full extent and condition of Iran’s enriched uranium reserves. According to Yousry Abushady, a veteran IAEA inspector, much of the material remains at Isfahan, likely dispersed among the three locations, though some may have been vaporized or reduced to microgram quantities by the blasts. Abushady suggests it may be more practical to abandon attempts to recover all residues rather than prolong fruitless searches.
Former US nuclear nonproliferation official Jon Wolfsthal concurs that the uranium is probably still in Iran and could potentially be exported within six months if the regime cooperates fully. However, he warns about the challenges posed if Iran withholds parts of its inventory or disputes what remains. Trust and transparency on both sides have long been obstacles. Iran suspended inspections following the bombings, and Washington’s withdrawal from the 2015 nuclear deal under President Trump precipitated a rapid expansion of Tehran’s nuclear program prior to last year’s strikes.
Under the 2015 agreement, Iran reduced its uranium enrichment to below 3.67 percent and shipped over 11,000 kilograms of higher-enriched uranium to Russia. Iranian negotiator Seyed Hossein Mousavian says Tehran had indicated willingness to dilute 60 percent enriched uranium again during recent talks, conditioned on the credibility of the agreement. However, renewed US military action complicated those discussions. Iran’s foreign minister, Abbas Araghchi, has rejected the idea of transferring enriched uranium abroad for dilution, insisting it be handled domestically, a point slated for negotiation before recent Israeli military actions in Lebanon prompted Tehran’s boycott.
The Trump administration’s demand for complete elimination of Iran’s enriched uranium, including nearly 10 metric tons of low-enriched uranium retained for civilian use, represents a departure from previous agreements that allowed limited enrichment for peaceful purposes. Despite diplomatic efforts led by special envoy Steve Witkoff and advisor Jared Kushner, skepticism remains among specialists regarding the likelihood of substantive progress in the near term.
The unresolved status of Iran’s nuclear material underlines the enduring complexity of preventing nuclear proliferation in the region. While the memorandum offers a framework for dialogue, the key issue remains verifying and securing all of Iran’s fissile material amid deep mutual mistrust and recent military conflicts.