US Secretary of State Marco Rubio begins a three-day trip to the United Arab Emirates, Kuwait and Bahrain on 23 June, the State Department confirmed, with the immediate task of reassuring Gulf allies disconcerted by the terms of the memorandum of understanding (MoU) signed with Iran last week. The visit, which includes a meeting with the Gulf Cooperation Council in Bahrain, comes as regional officials voice alarm over a proposed $300 billion reconstruction fund for Tehran and the MoU’s silence on Iran’s ballistic missile programme. According to the State Department, Rubio will also discuss efforts to secure free transit through the Strait of Hormuz.

Viewed from Gulf capitals, the central anxiety is that the reconstruction package—described in the MoU as a plan Washington “undertakes with regional partners to develop” with at least $300 billion—could enable Iran to rebuild military capacity and sustain proxy groups across the region. The UAE, Saudi Arabia, Kuwait, Bahrain and Qatar all host US military bases that form the backbone of America’s Middle Eastern security architecture, and all were targeted by Iranian missile and drone strikes during the recent conflict. While these states broadly supported diplomatic efforts to end the US-Israeli war with Iran, officials in the region have yet to indicate any willingness to contribute to the fund, and several have privately expressed concern that the MoU does not directly constrain Iran’s missile development.

In parallel, Vice President JD Vance disclosed in Switzerland a proposed mechanism for handling frozen Iranian assets should sanctions relief proceed. Under the plan, Washington and Qatar would jointly approve the release of funds, which would then be directed exclusively to purchases of American corn and wheat for the Iranian population. Vance attributed the model to Jared Kushner. The MoU itself stipulates that the implementation mechanism for the $300 billion plan will be finalised within 60 days as part of a comprehensive deal, a timeline that began with President Donald Trump’s signing of the document in Versailles on 18 June.

Rubio’s mission unfolds as technical talks continue in Switzerland, mediated by Qatari and Pakistani officials, following a first round that concluded on 23 June. The State Department has not released the precise schedule of Rubio’s bilateral meetings or the list of leaders he will engage. The outcome of the Gulf consultations is expected to shape the next phase of negotiations, with the 60-day clock for a final agreement already running and the question of who funds Iran’s reconstruction still unanswered.