2MAR

Putin renews HEU offer at SPIEF

3 min read

08:00UTC

Vladimir Putin restated Russia's offer to take custody of Iran's 440.9 kg highly enriched uranium stockpile at the St Petersburg forum on 6 June. It is the same arrangement Trump barred on 27 May.

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ConflictDeveloping

Key takeaway

Russia's HEU custody offer is the only live technical fix, and both Washington and Tehran have left it unanswered.

Vladimir Putin publicly restated Russia's standing offer to take custody of Iran's 440.9 kg stockpile of HEU (Highly Enriched Uranium, the 60 per cent material at the heart of the impasse) at the SPIEF (St Petersburg International Economic Forum) plenary on Saturday 6 June ¹. He added that Russia is not arming Iran, that Iran has requested no weapons, and that both the United States and Israel privately told Moscow that recent shelling near the Bushehr nuclear plant was accidental.

The custodian arrangement hands Iran a way to satisfy the US demand to remove the stockpile without surrendering it to Washington. Trump rejected precisely that arrangement at a Cabinet meeting on Wednesday 27 May, when he barred both Russia and China from the role and told his negotiators not to rush.

The offer follows Araghchi confirming no progress on the nuclear file , and it sits unanswered. Mojtaba Khamenei's order to keep the HEU inside Iran still stands, and Tehran has sent no counter-proposal since hand-editing the disputed deal text . Russia gains from being the only mediator both Washington and Tehran will still take calls from, so the offer serves Moscow's interest while remaining a concrete, deliverable route out of the deadlock.

Deep Analysis

In plain English

Iran has built up 440.9 kilograms of uranium enriched to 60 per cent purity. At 90 per cent, uranium becomes weapons-grade. The US and Israel want this stockpile removed from Iran or destroyed. Russia has repeatedly offered to take it to Russian territory for safekeeping. Putin made this offer again at SPIEF (St Petersburg International Economic Forum), Russia's annual economic conference, on 6 June. Iran's Supreme Leader has ordered the uranium stays inside Iran. As of 6 June, no custody transfer has been agreed and the war continues. Putin also said Russia is not supplying Iran with weapons, a denial that matters because US military assessments have previously linked Chinese and Russian equipment to Iran's continued military capability.

Deep Analysis

Root Causes

Russia's repeated reaffirmation of the HEU custodian offer across SPIEF (6 June), a Moscow press conference (10 May, ) and Peskov's statement (13 April, ) reflects a consistent Kremlin strategic interest: to prevent a US-Iran settlement that excludes Moscow from the regional architecture. Putin told SPIEF that 'initially everyone agreed' the uranium would go to Russia, a claim he has sole-sourced; if true, it positions the US as the party that hardened terms, not Iran.

Rosatom evacuated approximately 180 of its 200-plus staff from Bushehr by 16 April , leaving roughly 20 managers on site. Russia lacks the operational capacity to implement the custody arrangement even if Iran agreed.

Escalation

Putin's public denial that Russia is arming Iran is the most operationally significant element of the SPIEF statement. If accurate, it reduces the risk of a direct US-Russia confrontation over arms flows. The separate claim that both the US and Israel privately told Moscow the Bushehr shelling was accidental is unverifiable from the Russian side alone, but if true, it indicates an active US-Russia back-channel on escalation thresholds that has not been publicly acknowledged.

What could happen next?

Consequence
Russia positions itself as indispensable to any Iran settlement, complicating a purely US-Iran bilateral agreement.
Medium term · Assessed
Risk
Khamenei's order that the HEU stays inside Iran makes the custodian offer operationally moot until the Supreme Leader's position changes or his capacity to enforce it erodes.
Short term · Assessed
Opportunity
If Iran's economic collapse deepens, the custodian offer becomes Tehran's least-humiliating exit from the HEU impasse, enabling a deal without surrendering directly to the US.
Medium term · Reported

Source Landscape

This story draws on neutral-leaning sources

Primary parallel: The 2003-2006 Libya disarmament model, where Russia played no custodian role; Gaddafi surrendered his WMD programme directly to the US and UK after back-channel negotiations. Libya's willingness to hand material to a Western adversary is the precedent Washington wants to invoke; Tehran explicitly rejects it on the grounds that Libya was subsequently invaded.

Counter-parallel: The 1994 Budapest Memorandum, under which Ukraine surrendered its inherited Soviet nuclear arsenal to Russia in exchange for security guarantees. Russia's 2022 invasion of Ukraine is the canonical case Tehran cites when resisting any custody arrangement involving a third party.

Russia earns approximately $800m annually from the Bushehr reactor contract. Any custodian arrangement that returns Iran to IAEA compliance and lifts sanctions would reopen Iran's oil market to buyers who currently route around CENTCOM, reducing Iran's dependence on the Russia-China barter channel. Moscow benefits from Iran's economic isolation as long as it lasts; the custodian offer, if accepted, accelerates Iran's re-integration into the global economy and reduces Russian leverage.

For Iran, the $5.8bn revenue loss since April (event index 5) creates mounting pressure to accept any custody arrangement that unlocks sanctions relief. The economic pain and Putin's offer move in opposite directions on Tehran's willingness to concede.

Consensus view: Darya Dolzikova (RUSI) argues that Putin's custodian offer is structurally attractive to Iran as a face-saving device precisely because it avoids direct US custody, but is operationally undeliverable given Rosatom's evacuation of most staff from Bushehr and the physical barrier imposed by CENTCOM's blockade.

Counter-view: Fyodor Lukyanov, editor of Russia in Global Affairs and chair of the Council on Foreign and Defence Policy, has contended that Russia's real goal is to be present at any final settlement table, not to take custody; the offer is a diplomatic positioning move rather than a concrete proposal.

Key tension: Whether Mojtaba Khamenei's order that the stockpile remain inside Iran reflects a negotiating position or a constitutionally binding security doctrine that no interlocutor, including Russia, can shift.

First Reported In

Update #119 · Trump's Iran deal: 95% done, 0% signed

Press TV· 6 Jun 2026

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Causes and effects

This Event

Putin renews HEU offer at SPIEF

The one technical route out of the nuclear deadlock came from Moscow, not Washington. It lets Iran meet the US demand without conceding to Washington, which is why Trump blocked it and why Tehran has not taken it up.

Led to

Iran sends no nuclear counter to US

Putin reaffirmed the HEU custodian offer at SPIEF after Araghchi confirmed no progress on the nuclear file (ID:3887)

Occurred 4 Jun 2026

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IAEA loses track of Iran's uranium

Putin's 6 June SPIEF custodian reaffirmation is backdrop to the IAEA report making any custody clause unverifiable.

Occurred 4 Jun 2026

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US tables uranium draft at IAEA Board

Putin's SPIEF HEU custodian offer (ID:3937) is rendered unworkable alongside the US Board resolution, since the verification gap blocks any stockpile confirmation

Occurred 8 Jun 2026

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Different Perspectives

Oil markets / Lloyd's of London

Brent fell to near $87.33 on 80 per cent deal-probability pricing, but Lloyd's has not de-listed Hormuz from its war-risk register and shipping diversions continue at 139 vessels. Insurance markets are lagging futures: physical risk remains while financial markets have spent the good news before the paper exists.

India

Modi is expected to raise the deaths of three Indian sailors in the 11 June CENTCOM strike on the MT Settebello with Trump at G7 sidelines, the first non-party leader to put the blockade's human cost into a formal bilateral. New Delhi is also a major Iranian oil buyer whose import volumes the sanctions-relief terms will govern.

Israel (Netanyahu)

Netanyahu stated Israel is not party to the deal on 12 June; Defence Minister Katz ruled out the Lebanon withdrawal Iran's draft demands, inserting a third blocker the US-Iran negotiating channel cannot resolve. Israel's position tethers Hormuz reopening to a Lebanon settlement Washington has not brokered.

Pakistan (mediator, Sharif/Naqvi)

Sharif declared a final agreed text on 12 June before either principal confirmed it, running two Tehran visits in under a week without securing a written IRGC or Khamenei response. Islamabad's incentive to claim a diplomatic win outpaces its standing to deliver either capital's signature.

Iran foreign ministry (Araghchi)

Araghchi declared digital signing within days while setting dilute-in-Iran as a non-negotiable red line on the 440.9 kg HEU stockpile, a standing Tehran position he cannot override without authorisation from Khamenei, reachable only by courier. The FM track is sprinting to close before the IRGC reasserts control.

Trump administration / CENTCOM

Vance called the deal still TBD on 12 June while CENTCOM downed Iranian drones over Hormuz for a second consecutive night and the White House register stayed blank. Washington holds the ship-out position on HEU and has not signed an Iran instrument in over 100 days of conflict.