Iran-US war: Mohsen Rezaei says 'not a single gram of enriched uranium will leave Iran' — what we know so far

Mohsen Rezaei rejected sending Iran’s enriched uranium abroad and described the stockpile as national wealth for domestic use. His statement matters because the uranium stockpile is central to negotiations between Tehran and Washington. It also shows how closely Iran links nuclear policy with sanctions relief and national sovereignty.

After meeting Pakistan’s army chief Asim Munir in Tehran, Rezaei said that not a single gram would leave Iran. He also said there would be no negotiations until the United States took steps to build trust. Iran wants all its conditions fulfilled, including relief from pressure, threats, and sanctions.

The United States wants major limits on Iran’s enrichment capacity. Iran insists on retaining its right to enrich uranium and seeks sanctions relief, along with restored maritime traffic through the Strait of Hormuz. With inspections restricted and the JCPOA ended, the disagreement could keep negotiations stalled.

Enriched uranium is uranium processed to increase the concentration of uranium-235, or U-235. Natural uranium contains mostly U-238 and only a small amount of U-235. The distinction matters because U-235 can sustain the fission reaction that releases energy. That energy supports peaceful nuclear power and can also be used in weapons.

For reactors, uranium is generally enriched to produce suitable fuel. Iran says its enrichment program serves domestic nuclear reactors and peaceful purposes. The article reports that Iran holds uranium enriched to levels as high as 20 percent and 60 percent U-235, far above the 3.67 percent limit set by the 2015 JCPOA.

Higher enrichment does not itself prove a weapons program, and Tehran denies pursuing nuclear weapons. However, the IAEA says concerns about Iran’s potential capabilities have not been fully dispelled. The United States therefore seeks concrete reductions, not only assurances.

The IAEA assessed that Iran’s enriched uranium stockpile remains in the country. Its reported figures include 184.1 kilograms of uranium hexafluoride, or UF6, containing up to 20 percent U-235, and 440.9 kilograms of UF6 containing up to 60 percent U-235. Together, those categories total 625 kilograms.

These levels matter because enrichment raises the concentration of uranium-235. The 2015 JCPOA allowed no more than 300 kilograms of UF6 containing 3.67 percent U-235, or an equivalent amount in another chemical form. Iran’s reported stockpile therefore exceeds the agreement’s stated limit in both quantity and enrichment level.

The article also cites an IAEA estimate of more than 400 kilograms of highly enriched uranium, enough for several nuclear weapons if further refined. The stockpile is primarily stored at known sites in Isfahan, Fordow, and Natanz. Tehran denies seeking nuclear weapons and says the material supports peaceful reactors.

The United States wants substantial restrictions because Iran’s expanded enrichment program has reduced the time needed to produce enough weapons-grade highly enriched uranium, a process often called breakout. Washington questions why Iran needs uranium enriched to 60 percent if it does not intend to build a weapon. It wants concrete action rather than assurances.

Iran presents the issue differently. Tehran says enrichment is for domestic nuclear reactors and repeatedly emphasizes its right to enrich uranium. A senior Iranian official called recognition of that right a red line, while leaving the details and scale of enrichment open to later discussion. Iran also seeks relief from the US blockade and sanctions.

The disagreement is therefore about both security and sovereignty. The United States prioritizes limits that reduce possible weapons risks. Iran prioritizes retaining enrichment rights and ending economic pressure. Neither side’s stated priority fully matches the other’s, making an agreement difficult.

A refusal to send enriched uranium abroad would remove one possible concession in negotiations. If the United States also refuses to ease sanctions, Iran’s stated conditions for restarting talks would remain unmet. Rezaei said there would be no negotiations until Washington takes trust-building steps and fulfills all of Iran’s conditions.

The central mechanism is reciprocal pressure. Iran holds its stockpile and insists on its enrichment rights, while the United States seeks substantial limits on enrichment and uses sanctions as leverage. The article also says Tehran wants pressure and threats lifted, alongside restored maritime traffic through the Strait of Hormuz. Neither side has accepted the other’s priorities.

The immediate result could be continued diplomatic deadlock, with the nuclear issue unresolved. The article says Iran has declined to let IAEA inspectors resume inspections, and that the June 2025 attacks set back the program but left its fate unresolved. Future progress would require changes by both sides.

The 2015 Joint Comprehensive Plan of Action limited Iran’s enriched uranium stockpile to 300 kilograms of UF6 containing 3.67 percent U-235, or an equivalent quantity in another chemical form. These limits were designed to constrain the amount and concentration of Iran’s enriched material. Iran initially limited enrichment-related activities and stopped work on heavy-water-related projects under the agreement.

The situation changed after the United States withdrew from the JCPOA in 2018. Iran began enriching uranium again. The article says that before the US strikes in June 2025, Iran’s centrifuges, stockpile size, enrichment concentration, and number of enrichment locations exceeded JCPOA limits.

The IAEA later reported 184.1 kilograms enriched up to 20 percent and 440.9 kilograms up to 60 percent. In October 2025, Iran officially ended the JCPOA and declared its nuclear restrictions void. The agreement’s limits therefore no longer guide Iran’s declared position.

Centrifuges increase uranium-235 concentration by spinning uranium gas rapidly. The heavier U-238 moves slightly differently from the lighter U-235, allowing repeated centrifuge stages to separate the isotopes. Each stage makes only a small change, but many stages can progressively raise the U-235 share. The article identifies U-235 as the isotope central to fission.

The mechanism becomes faster at higher starting enrichment. Material already enriched to 20 or 60 percent contains much more U-235 than natural uranium. Further processing therefore needs less separation work to reach weapons-grade highly enriched uranium. This is why the United States focuses on Iran’s enrichment capacity and stockpile, not only its stated intentions.

The article says Iran’s expansion since 2019 reduced the time needed to produce enough weapons-grade HEU, a possibility called breakout. Tehran denies seeking weapons and says enrichment supports peaceful reactors. The IAEA says concerns about potential capabilities remain unresolved.