President Donald Trump said on June 14 that a deal to solve the US conflict with Iran had been finalised, while announcing the immediate termination of the US naval blockade of the Islamic Republic as well as what he described as the “toll-free” reopening of the Strait of Hormuz.

In a post published on June 15 on Truth Social, Trump said he was ordering the withdrawal of US naval vessels and urging maritime traffic to prepare to pass through the Hormuz transit corridor chokepoint, he wrote: “Ships of the World, start your engines.”

US Vice President JD Vance characterised the memorandum of understanding agreed between Washington and Tehran as a brief and largely non-specific document, describing it as roughly a page and a half in length and “very general”.

The agreement gives both governments 60 days to tackle issues that remained unresolved before the first US-Israeli military campaign launched against Iran in June last year and ahead of the subsequent conflict ignited with air force and missile attacks on Iran at the end of February. As part of that, negotiators are to seek to establish mutually acceptable constraints on Iran’s nuclear activities in exchange for economic concessions from Washington.

Iran’s nuclear programme remains the most sensitive matter in determining the way ahead. The country is believed to possesses around 440 kilograms of uranium reserves that are mostly purified to near-weapons grade 60%, according to various media reports. Specialists estimate that, if enriched to weapons-grade purity of 90%, the quantity could be sufficient for roughly 10 nuclear weapons. The future disposition of the stockpile has thus become one of the most difficult points of contention, with Trump having previously insisted that the material be removed from Iranian territory.

Given these circumstances, some observers have suggested that Kazakhstan, Iran’s neighbour across the Caspian Sea, could end up playing a key role in making sure the overall peace deal is finalised successfully. 

Kazakhstan proposed as host for uranium 

A supervised uranium escrow mechanism supervised by the International Atomic Energy Agency (IAEA) and based in Kazakhstan could provide a solution to the enriched uranium dilemma, according to an opinion piece written by advisor to the chairman of the Board for International Affairs and Initiatives at Maqsut Narikbayev University in Astana, Miras Zhiyenbayev, and published by The National Interest on June 9. The article followed comments made by IAEA director-general Rafael Grossi in an interview with the Financial Times, in which he said Kazakhstan had indicated its willingness to receive Iran’s stockpile of uranium enriched to 60% should Washington and Tehran reach a nuclear accord. Grossi said the matter was discussed during talks with Kazakh President Kassym-Jomart Tokayev in Astana in May.

Grossi told the FT that “we have a place where this could be stored safely” since the IAEA has a low-enriched uranium “bank” in Kazakhstan. 

IAEA uranium fuel bank at Kazatomprom's Ulba Metallurgical Plant in Oskemen, East Kazakhstan  (Credit: NAC Kazatomprom JSC, cc-by-sa 4.0).

Discussing efforts to revive the nuclear agreement that prior to Trump’s first term in office existed between the US and Iran, Zhiyenbayev argued that the principal challenge lies in determining how Iran’s highly enriched uranium reserves should be managed.

While Washington has sought to ensure that sensitive nuclear material is kept beyond Tehran’s immediate control, Iranian authorities have historically resisted sending uranium abroad, viewing such proposals as an infringement on national sovereignty.

Under the proposal outlined in the article, uranium considered most sensitive from a nuclear proliferation perspective would be transferred to Kazakhstan and held under IAEA oversight, rather than being sent to the US, Russia or China. Zhiyenbayev argued that such a framework could represent a compromise, placing the material under international supervision while avoiding the impression that Iran had ceded control directly to a major power.

The author also pointed to Kazakhstan’s longstanding non-proliferation record, including its decision to relinquish the Soviet nuclear arsenal it inherited after independence and its role as host of the IAEA Low Enriched Uranium Bank at the Ulba Metallurgical Plant in Oskemen.

“This is why Kazakhstan is useful in a way Russia is not,” Zhiyenbayev wrote. “Moscow has the technical infrastructure, but it is politically the wrong answer. Any arrangement that gives Russia a central role in a US-Iran settlement would immediately become entangled in the Ukraine War, sanctions politics, and the perception that Moscow was being rewarded with diplomatic leverage at Washington’s expense.”

“China would raise a different but related problem,” he added. “Beijing may have the technical capacity, but placing Iran’s most sensitive material under Chinese custody would create a new geopolitical vulnerability inside a deal already burdened by mistrust. Trump himself has shown little appetite for an arrangement that leaves the stockpile in Russian or Chinese hands.”

As such, Zhiyenabyev posited that “Kazakhstan is a nonproliferation-minded middle power with a record Washington can defend and Tehran could accept without appearing to capitulate to the United States.”

Under the Kazakhstan proposal, the US would receive assurances that proliferation-sensitive material was outside Iran’s direct reach, while Tehran could maintain that the uranium remained under an international framework rather than the control of a geopolitical competitor, he noted.

He argued that although a Kazakhstan-based escrow system would not resolve wider disagreements surrounding Iran’s nuclear programme, it could offer a credible and verifiable mechanism for addressing one of the negotiations’ most difficult outstanding issues.

Ulba Metallurgical Plant

Should Tehran accept Kazakhstan’s proposal to store its uranium stockpile at the Ulba Metallurgical Plant as part of a broader settlement with Washington, it would not be the first occasion that the Soviet-era facility had played a central role in the handling of strategically significant nuclear material, RFE/RL reported on June 6.

In 1993, Andy Weber, a young US diplomat newly posted to independent Kazakhstan, was approached by Vitaly Mette, director of the metallurgical complex in the northeastern city of Ust-Kamenogorsk, now known as Oskemen, the news outlet’s report said.

Mette offered what he said was 600 kilograms of highly enriched uranium, a quantity sufficient to produce dozens of nuclear warheads. The material had remained unused at the facility since the cancellation of a Soviet nuclear submarine programme in 1981. The uranium, originally intended as fuel for attack submarines, had effectively been forgotten after the Soviet Union’s collapse, while Moscow no longer exercised authority over the plant.

At a time when Iranian operatives were reportedly active across Central Asia seeking Soviet-era nuclear materials, Weber quickly informed US officials of the proposal, the report said. When the issue was raised with then Kazakh president Nursultan Nazarbayev, he did not object to the possibility of the US removing material associated with a Soviet nuclear legacy that had caused extensive environmental and health damage across Kazakhstan.

Weber and a US nuclear specialist subsequently travelled to Ust-Kamenogorsk, where they were shown containers holding metal rods inside a building at the Ulba facility secured by what was described as an antiquated padlock, according to the report. Tests confirmed the material consisted of uranium enriched to 90% uranium-235, prompting alarm in Washington.

In October 1994, 31 American technicians and specialists arrived in Ust-Kamenogorsk to conduct a covert mission aimed at securing and removing the uranium. The operation, known as Project Sapphire, lasted nearly a month. It involved a team packaging 581kg of uranium into 448 foam-lined metal barrels before transporting it out of Kazakhstan.

Concerns that Iran might have sought access to the material gained credibility when workers discovered crates of beryllium at the plant addressed to Tehran but never shipped.

So, back to the present, is Kazakhstan ready to assist the US on another Iran-related (and uranium-related) matter once again? 

President Tokayev has already welcomed the peace memorandum agreed between Washington and Tehran. With negotiations over the detailed terms of any long-term settlement still ongoing, Kazakhstan may yet have an opportunity to play a further role in supporting efforts to resolve the Iranian nuclear issue.

Neither the Kazakh government nor the IAEA has announced any formal agreement regarding the possible transfer or storage of Iranian uranium, but the offer appears to be very much on the table, given Grossi’s comments.