US Secretary of State Marco Rubio begins a three-day visit to the United Arab Emirates, Kuwait and Bahrain on Tuesday, the State Department confirmed. The trip, his first to the region since the US-Israeli military campaign against Iran began in February, is scheduled to include a meeting with the six-member Gulf Cooperation Council in Manama. According to State Department spokesperson Tommy Pigott, Rubio will discuss the memorandum of understanding signed with Iran, efforts to guarantee full and secure transit through the Strait of Hormuz, and the importance of regional peace and stability.

Gulf capitals have publicly backed the cessation of hostilities but, according to regional officials cited by Western news agencies, harbour deep reservations about the MoU’s specifics. The possibility of a $300 billion reconstruction fund for Tehran is viewed with suspicion; Gulf leaders assess that the Islamic Republic would channel the resources into rebuilding its military capacity and financing allied armed groups across the Middle East. The absence of any provision addressing Iran’s ballistic missile programme is a further source of disquiet, given that several GCC states have been struck by Iranian missiles and drones in recent months. All five GCC members that host US military bases — the UAE, Saudi Arabia, Kuwait, Bahrain and Qatar — form the backbone of America’s regional force posture, and any recalibration of those security ties, even a subtle one, could alter US military strategy, Western diplomatic sources note.

The Rubio mission unfolds amid an intensive diplomatic sequence. President Donald Trump signed the MoU with Iran on 18 June in Versailles, alongside French President Emmanuel Macron, triggering a 60-day deadline for negotiators to reach a comprehensive agreement. Over the weekend, a US team led by Vice President JD Vance attended talks in Switzerland mediated by Qatari and Pakistani officials; a first round concluded on Monday and technical discussions are expected to continue through the week. From Tehran, Foreign Minister Abbas Araghchi stated that the negotiations have made “significant progress” and are advancing in line with Iran’s positions and demands. The GCC is expected to assume a role in implementing elements of the accord, particularly those related to the Strait of Hormuz, through which roughly one-fifth of global oil supplies transit and which Iran had closed during the conflict.

Rubio, who also holds the White House national security advisor portfolio, will use the Manama stop to discuss “shared priorities across the region” with the GCC, the State Department said. The precise schedule of bilateral meetings and the list of leaders he will see have not been released. The technical talks in Switzerland are set to continue this week, with the 60-day clock for a final agreement already running.