President Donald Trump reiterated Thursday that the United States will not allow Iran to continue stockpiling highly enriched uranium.
However, Iran’s Supreme Leader Mojtaba Khamenei has issued a directive that Iran’s enriched uranium should not be sent outside the country, Reuters reported on Thursday, citing two unnamed Iranian officials.
The future of the estimated 440 kilograms (970 pounds) of 60% enriched uranium Iran is believed to have remains a key issue in peace talks between the United States and Iran.
Nuclear experts say 60% uranium enrichment is still a long way from the 90% needed for weapons-grade material, but it is a point at which 90% will be reached much sooner.
But even if Iran agrees to the transfer, can highly enriched uranium be safely moved between countries?
Here’s what we know:
What do President Trump and Khamenei say about enriched uranium stockpiles?
“We’re going to have it. We don’t need it, we don’t want it. If we get it, we’ll probably destroy it, but we’re not going to let them have it,” Trump told reporters at the White House on Thursday, referring to Iran’s enriched uranium stockpile.
However, on the same day, Reuters reported that Iran’s supreme leader had issued a directive banning the extraction of uranium.
Reuters also reported, citing unnamed Israeli officials, that President Trump assured Israel that Iran’s enriched uranium stockpile would be shipped out of Iran and that any peace agreement would include provisions regarding this.
“The Supreme Leader’s directive and the consensus within the regime is that enriched uranium stockpiles should not be taken out of the country,” Reuters reported, citing one of two Iranian intelligence sources who spoke on condition of anonymity due to the sensitivity of the matter.
What do we know about Iran’s enriched uranium?
The Iranian government has long maintained that its nuclear program is for civilian purposes only and that it has no intention of building nuclear weapons. In 2015, it signed an agreement with the United States that limited its nuclear program in exchange for sanctions relief. But President Trump withdrew from the landmark deal in 2018 and reimposed sanctions on Iran, even though international inspectors said Iran was sticking to its side of the deal.
In the wake of the United States’ withdrawal from the agreement, known as the Joint Comprehensive Plan of Action (JCPOA), and the 2021 bombing of Iran’s Natanz nuclear facility, which Iran blamed on Israel, Iran has decided to enrich uranium from the 3.67% allowed under the 2015 agreement to almost 60% for nuclear power development purposes.
Iran is currently believed to have around 440 kg (970 lb) of 60% enriched uranium. Producing nuclear weapons requires 90 percent enriched uranium.
In theory, this amount of enriched uranium, if enriched to 90 percent, would be enough to make more than 10 nuclear warheads, International Atomic Energy Agency Director General Rafael Grossi told Al Jazeera in early March.
Most of Iran’s stockpiles are believed to be in the form of hexafluoride gas, which can be stored in small containers the size of scuba tanks. This is spun in a centrifuge to increase the proportion of uranium-235, an isotope that promotes nuclear fission chain reactions.
Most of Iran’s enriched uranium is believed to lie underground, beneath the rubble of Iranian nuclear facilities bombed by the United States and Israel during last year’s 12-day Iran-Israel war. In June 2025, President Trump said that three Iranian nuclear enrichment facilities in Fordow, Natanz and Isfahan had been “destroyed” by US strikes.
But Israel, the United States, and other Western countries now claim that Iran is seeking, or at least preparing, the ability to build nuclear weapons. They argue that the 60 percent enrichment levels achieved so far far exceed the levels needed for civil nuclear energy programs.
Israeli Prime Minister Benjamin Netanyahu said the war will not be considered over until Iran’s enriched uranium is removed, Iran stops supporting regional proxy armed groups and its ballistic missile capabilities are dismantled.
What will happen to Iran’s enriched uranium?
The United States wants to hand over the shares, but Iran reportedly intends to only consider transferring them to a third party. Currently, Supreme Leader Ayatollah Khamenei is said to have issued an order prohibiting any removal.
Iran and the United States have reached an “impasse” over Iran’s “enriched materials” issue, Iran’s top diplomat Abbas Araghchi told reporters on the sidelines of the BRICS foreign ministers’ meeting in New Delhi earlier this month.
As a result, he said, the topic had been “postponed” until a later stage of negotiations. “For the time being, it is not being discussed or in negotiations, but we will take up this matter at a later stage.”
Meanwhile, during informal negotiations with the US in Geneva on February 26 this year, two days before the US and Israel launched their attack on Tehran, Iran reportedly proposed to “down-blend” its stockpiles from 60 percent to 3.67 percent in an irreversible process.
Can enriched uranium be transported safely?
Uranium hexafluoride gas is extremely dangerous. If released, it can form highly toxic and corrosive fluoride compounds that are fatal if inhaled and can burn the skin.
The IAEA has established specific procedures for safely transporting enriched uranium. According to the agency’s website, enriched uranium hexafluoride can be transported in Type 30B containers, which are heavily reinforced, standardized steel cylinders. These are specially designed to withstand high pressure and heat.
The IAEA also said the cylinders were intentionally made small to “avoid criticality risks.” In this context, “critical” means an uncontrolled nuclear chain reaction that releases energy and radiation very quickly.
Has enriched uranium been transferred in the past?
The United States had been exporting highly enriched uranium to Canada for medical isotope production since the mid-1980s, but that export was phased out as producers converted to less enriched uranium. By the mid-2010s, the U.S. government allowed what it called final exports, and in 2021 the U.S. Department of Energy announced it would stop supplying enriched uranium for medical isotope production, citing the successful transition of global markets to lower enriched uranium.
After the Cold War, the U.S. military flew about 600 kg (1,323 pounds) of weapons-grade uranium from Kazakhstan in 1994 in a covert operation called “Project Sapphire” to remove residual nuclear material from the Soviet Union.
The Center for Arms Control and Nonproliferation said the team involved in the shipment worked 12-hour shifts, six days a week, for four weeks just to safely transport the materials from the metallurgical plant to the local airport.
