On Thursday, Iran’s Islamic Revolutionary Guard Corps (IRGC) declared that safe passage through the Strait of Hormuz is only possible via routes officially designated by Tehran, and warned that any vessel using an alternative corridor would face enforcement measures. The statement, carried by state media, described a newly announced shipping route—an apparent reference to a temporary corridor unveiled overnight by Oman—as “unacceptable and extremely dangerous.” The IRGC insisted that all ships must coordinate with its naval forces through international maritime Channel 16 and that the sole authorised transit lane is the one running close to the Iranian coast.

The IRGC’s intervention directly challenges Oman’s initiative, which Muscat said was coordinated with the International Maritime Organisation and established a mine-free route through Omani territorial waters to facilitate the resumption of commercial traffic. Viewed from Tehran, the Omani corridor undermines Iran’s claim to regulate the strait, a position reinforced by the IRGC’s warning that navigation outside Iranian-designated routes is prohibited. The United States, meanwhile, has rejected any Iranian attempt to impose fees or controls on the waterway. Speaking at a Gulf Cooperation Council meeting in Bahrain, US Secretary of State Marco Rubio said that accepting tolls on an international strait would “spread throughout the world like a contagion” and risk “total chaos.” He added that Washington seeks a verifiable peace deal with Iran but “not at any price.”

The dispute over transit routes and potential charges is the most visible friction point in the fragile post-war arrangement. A memorandum of understanding signed by the US and Iranian presidents on 17 June ended four months of hostilities and stipulated that commercial vessels may transit the strait free of charge for 60 days while negotiators work toward a final agreement. Iran, however, has signalled that it intends to impose what it calls maritime service fees thereafter, and has established a tripartite classification of states—friendly, neutral, and hostile—that determines access and costs. Analysts in London note that even a partial Iranian operational control over Hormuz could permanently reduce oil tanker traffic below pre-war levels, as shippers and insurers factor in the risk of unilateral enforcement actions.

The strait, a 30-kilometre-wide chokepoint through which roughly one-fifth of global crude oil and liquefied natural gas normally passes, was effectively blockaded by Iran after the US and Israel launched strikes on 28 February. The IRGC’s latest warning underscores Tehran’s determination to retain the strategic leverage it gained during the conflict, even as formal negotiations continue. With the 60-day free-passage window ticking, the unresolved status of the waterway—and the competing claims of Oman, Iran, and the international community—remains the central obstacle to a durable settlement. The next round of talks is expected to address the strait’s governance, but the IRGC’s statement suggests that Iran’s security apparatus will resist any arrangement that dilutes its de facto authority over the passage.