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Iran Conflict 2026
1JUN

Trump vetoes Iran's only uranium exit

4 min read
08:32UTC

Asked at a 27 May Cabinet meeting whether Iran could ship its uranium to Russia or China, Donald Trump said "No, I wouldn't be comfortable", shutting the one storage route that could have bridged the deal.

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Key takeaway

On Day 90 the only actor visibly slowing an Iran settlement is the US President, by act not word.

Donald Trump rejected both Russia and China as custodians for Iran's highly enriched uranium at a 27 May Cabinet meeting in Washington, telling reporters "No, I wouldn't be comfortable" with either 1. The answer killed the only third-country storage option anyone had floated. Iran holds roughly 440.9 kg of uranium enriched to 60%, far above reactor fuel and a short technical step from weapons-grade, at the Isfahan tunnel complex. The International Atomic Energy Agency (IAEA), the UN body that verifies nuclear material, has had no access since 28 February, so no outside party can even confirm where the stockpile now sits.

Supreme Leader Mojtaba Khamenei had ordered the material to stay inside Iran on 21 May , reversing a pre-war offer to export half and removing the export option outright. Sending it abroad under a neutral host was the workaround, and Vladimir Putin had pitched Xi Jinping in Beijing on 21 May that Russia would hold it. By barring both Russia and China without naming a fourth host, Trump struck out the last route between the US demand that the uranium leave and Iran's refusal to let it go, hardening the three-way split that had already produced contradictory accounts of the deal's nuclear terms .

The same afternoon, Trump told his negotiators "not to rush into a deal" and said Iran's hope of outlasting him "won't work because I don't care about the midterms" 2. Marco Rubio, his Secretary of State, had said 24 hours earlier the deal could be finalised that day. A fairer reading deserves its sentence: with Iran refusing both to surrender the uranium and to readmit inspectors, barring Moscow and Beijing as custodians is defensible non-proliferation rather than gamesmanship.

The ledger cuts against that reading. The White House presidential-actions index shows zero Iran instruments signed across 90 days of war 3: no ceasefire order, no use-of-force authorisation, nothing directing or limiting the naval blockade. The veto is an act, not a post, and it points the same way 90 days of silence have: away from closure.

Deep Analysis

In plain English

Iran has a stockpile of uranium enriched to 60% purity. Normal power-station fuel sits around 5%. Weapons-grade uranium needs to be about 90% pure. Iran's 60% material is not yet weapons-grade, but it is close enough that further enrichment to weapons-grade would be a relatively short technical step. The US wants Iran to get rid of this stockpile before a deal is agreed. The idea was to ship it to a third country, like Russia, for safekeeping. Trump has now said he doesn't trust Russia or China to hold it securely. So there is no agreed destination, and Iran itself has said the material is staying inside the country. Both sides have now closed off the workaround diplomats had been quietly working towards for weeks: Trump vetoed the custodian, and Khamenei barred the export. Neither move has been reversed.

Deep Analysis
Root Causes

The third-country custody impasse has two structural roots that pre-date 27 May.

First, the IAEA was locked out of Iran at the start of the conflict following the Majlis's 221-0 vote suspending all cooperation. Without IAEA inspectors, no independent party can verify where the 440.9 kg stockpile actually is, whether it has been further enriched since the lock-out, or whether a transfer has been completed honestly.

Russia and China both lack the independent inspection capacity to substitute for the IAEA. Trump's stated discomfort with both as custodians is partly a verification problem: neither country would accept intrusive IAEA-style access on its own soil to monitor the transferred material.

Second, Mojtaba Khamenei's 21 May directive ordering the stockpile to remain in Iran removed Iran's negotiating flexibility on the very item the US identified as the last sticking point. Rubio named HEU turnover as the final unresolved issue; Khamenei's directive closed the export option, and Trump's 27 May veto closed the custodian workaround, in the same week.

Escalation

The 27 May veto raises the diplomatic ceiling required to reach any agreement. Any path forward now requires either a new custodian state that Trump trusts, a mechanism for Iran to dispose of the material inside Iran itself with verified destruction, or an Iranian reversal of Khamenei's 21 May directive. None of those three options is currently on the table.

What could happen next?
  • Consequence

    With Russia and China vetoed, there is no third-country custody mechanism available. Any resumed negotiation must find a new sequencing bridge for the HEU question or defer it entirely to Phase 2.

    Immediate · Assessed
  • Risk

    Iran's 440.9 kg stockpile at 60% enrichment continues to accumulate without IAEA oversight. The breakout timeline shortens every week the IAEA remains locked out, regardless of diplomatic progress on other tracks.

    Short term · Assessed
  • Precedent

    Trump's explicit rejection of Russia and China as custodians formalises a great-power split over the Iran nuclear file. Any eventual settlement must now be US-managed or US-endorsed, eliminating multilateral burden-sharing.

    Medium term · Reported
  • Risk

    If negotiations collapse permanently, Iran's enrichment programme resumes unrestricted. The Arms Control Association estimates Iran could reach weapons-grade enrichment within weeks from the current 60% baseline.

    Long term · Suggested
Sources:CNBC·PBS News·PBS News
Mentions:Donald Trump →Iran →Russia →China →Vladimir Putin →Xi Jinping →Marco Rubio →Pakistan →Strategic Council on Foreign Relations →Isfahan →Tasnim →Tennessee →Arms Control Association →Tehran →Beijing →Gaddafi →Libya →Kazakhstan →NATO →Moscow →Washington →United States →Council on Foreign Relations →Isfahan tunnel complex →IAEA →Mojtaba Khamenei →White House →
First Reported In

Update #110 · Trump vetoes Iran's only uranium exit

CNBC· 28 May 2026
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Causes and effects
Caused by
Khamenei orders the uranium to stay
Khamenei's 21 May directive ordering the HEU stockpile to stay in Iran created the impasse that Trump's veto of Russia and China as custodians closes off; the directive removed the export option and the veto removes the workaround.
Occurred 21 May 2026
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Hegseth threatens Iran strikes in Singapore
Hegseth's Shangri-La remarks linking Hormuz to Taiwan follow Trump's barring of China as HEU custodian on 27 May; China's scholars-only delegation is consistent with that exclusion.
Occurred 30 May 2026
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This Event
Trump vetoes Iran's only uranium exit
The veto removes the only third-country custody arrangement that could have reconciled the US demand to surrender Iran's uranium with Tehran's refusal to give it up.
Led to
Iran airs draft deal; US calls it fake
Trump's Cabinet veto of third-country custody options sharpened the document war by making the MOU's bracketed Hormuz-sovereignty and US-force-posture clauses the only remaining open-text disputes.
Occurred 27 May 2026
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US sanctions the strait it will reopen
Trump's decision not to sign the MOU on 28 May followed his 27 May Cabinet instruction to slow down and bar Russia and China as HEU custodians.
Occurred 28 May 2026
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Iran and US publish two different deals
Trump barring Russia and China as HEU custodians on 27 May left the deal's hardest item without an agreed location, amplifying the incompatibility of the two published MOU texts.
Occurred 29 May 2026
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Different Perspectives
Human rights monitors (Hengaw, Amnesty International, Iran HRM)
Human rights monitors (Hengaw, Amnesty International, Iran HRM)
Monitors documented a second death sentence for Zahra Tabari, 68, reported cemetery record deletions at Behesht-e Zahra, and a poll showing 81.5% of medical residents want to emigrate, against a background of 200+ confirmed executions since February. Iran's security courts operate at uninterrupted wartime tempo regardless of the diplomatic track.
Pakistan (mediator)
Pakistan (mediator)
Islamabad carried Trump's revised MOU demanding HEU destruction to Iranian negotiators, formally inheriting the role of sole active mediator after Oman's forced withdrawal. Pakistan lacks Oman's banking infrastructure for frozen-asset routing and carries its own regional stakes, making it a less structurally neutral broker.
Kuwait
Kuwait
Kuwait intercepted Iranian missiles and drones for a second time in days on 1 June, with air-raid sirens sounding nationwide, after invoking Article 51 self-defence on 28 May following the Ali Al Salem ballistic-missile strike. The repeated interceptions test whether Kuwait's domestic politics can sustain hosting US forces as a de facto co-belligerent.
China (PRC)
China (PRC)
Beijing sent scholars to Shangri-La rather than its defence minister and addressed Taiwan without mentioning Iran, maintaining bilateral energy corridor protection with Tehran while refusing diplomatic exposure at multilateral forums. Trump barred China as an HEU custodian on 27 May, removing Beijing from the deal architecture while China continues supplying DPI hardware that caps Iran's internet.
Lloyd's of London / war-risk underwriters
Lloyd's of London / war-risk underwriters
Lloyd's held its Hormuz war-risk designation at $10-14 million per voyage while Brent recovered to $93.91, maintaining the structural divergence from futures pricing that has persisted since late May. Underwriters require a UN Security Council resolution or government certification letter, not diplomatic optimism.
Gulf Cooperation Council states (Saudi Arabia, UAE, Bahrain, Qatar)
Gulf Cooperation Council states (Saudi Arabia, UAE, Bahrain, Qatar)
Five Gulf states wrote to the IMO on 21 May rejecting Iran's PGSA transit authority over international waters; Saudi Arabia and the UAE have not confirmed participation in the European Hormuz mission. The GCC is navigating between US security guarantees and exposure to Iranian fire, with no Gulf state formally co-belligerent except Kuwait.