Every diplomatic framework has a single hardest element — the concession that one side cannot easily make and the other side cannot easily withdraw. In the Iran war MOU, that element is now confirmed and publicly reported: Iran must physically surrender 440 kilograms of uranium enriched to 60% purity.
What 440kg of 60%-Enriched Uranium Actually Is
According to US media reports, Iran would also be required to hand over an estimated 440kg (970lb) stock of uranium, which it has enriched to 60 percent.
Two sources with knowledge also claimed Iran would agree to remove its highly enriched uranium from the country, a key US priority that Tehran has rejected up to now. One source said an option being discussed is moving the material to the US.
Natural uranium contains 0.7% of the fissile isotope U-235. Weapons-grade uranium is enriched to 90% or above. The JCPOA limited Iran to 3.67% enrichment. Iran has been enriching to 60% — the highest level it has publicly acknowledged, far beyond any civilian nuclear energy requirement.
Sixty percent enriched uranium cannot be directly used in a weapon, but it requires significantly less additional work to reach weapons grade than low-enriched uranium. The IAEA has assessed Iran’s 440kg stockpile as the largest single proliferation risk in the non-weapons-state nuclear landscape.
Why the IRGC Blocks This Demand
For Iran’s IRGC hardliners, surrendering the 440kg stockpile is not a technical nuclear decision — it is a strategic and symbolic one. The stockpile represents years of industrial effort, defiance of international sanctions, and the most visible product of Iran’s nuclear programme.
Surrendering it physically — putting it in boxes, loading it on planes, watching it leave Iranian soil — is the kind of visible, reversible concession that hardliners cannot frame as anything other than defeat.
Iran has said it is “still reviewing” the proposal. Some analysts say Iran may have to change its tone on its nuclear programme.
The analysts who say Iran may have to “change its tone” are identifying the specific calculation that Kharg Island’s filling storage tanks are forcing: the economic cost of the blockade continuing is now potentially larger than the political cost of the HEU concession. When wells shut down, the damage is permanent and takes years to reverse.
The HEU stockpile is a strategic asset — but a strategic asset with zero immediate utility because Iran has committed not to weaponise it. If it goes to Russia, a multilateral body, or even the US, Iran preserves the right to say it did not develop a bomb — which is also its consistent public position.
The Possible Bridges
Three mechanisms have been discussed for the 440kg transfer. Russia custody was the first proposal — Putin offered to hold Iran’s HEU. Trump reportedly rejected this because it gives Russia geopolitical leverage. Multilateral IAEA custody was the second — a UN-supervised storage arrangement that neither Iran nor the US controls.
The US as recipient was the third option — Axios confirmed this is “being discussed,” which would satisfy the US demand for control while giving Iran the argument that it cooperated with international nuclear non-proliferation norms.
The 30-day negotiating period in the MOU is specifically designed to allow the detailed transfer mechanism to be worked out after the framework is agreed. Iran does not need to commit to giving the 440kg to the United States in the one-page MOU — it needs to commit to removing it from Iran within the 30-day negotiating period. How it moves, and to whom, is the subject of the subsequent detailed negotiation.
That distinction — commit to removal now, agree mechanism later — is what separates “wish-list” from “workable deal” in Iran’s internal assessment. If the MOU commits to the principle of removal rather than the specific mechanism, Iran’s civilian team may be able to sell it to the IRGC as a framework that preserves future flexibility on the details.
