Iran Closes Strait of Hormuz in Escalation Over Alleged US Breach of Islamabad MoU

Iran has announced the full closure of the strategically vital Strait of Hormuz, citing the United States’ failure to uphold key provisions of the Islamabad Memorandum of Understanding (MoU), according to Iranian state media.

The announcement, reported by Tehran Times and other state outlets, marks a sharp escalation in tensions between Tehran and Washington. It comes amid fragile ceasefire efforts following months of conflict. Iranian officials described the move as a direct response to perceived violations by the US and its allies, particularly regarding commitments tied to the recent MoU mediated with Pakistani involvement.

“Iran announces full closure of the Strait of Hormuz in response to the US failure to uphold the Islamabad MoU,” the state media outlet declared, framing the decision as necessary to protect Iranian interests and enforce compliance with the agreement.

The closure threatens to disrupt global oil supplies, as the narrow waterway between the Persian Gulf and the Gulf of Oman handles roughly one-fifth of the world’s seaborne crude oil shipments. Shipping data has shown reduced transits in recent periods amid ongoing disputes.

Separately, Iranian Parliament Speaker Mohammad Bagher Ghalibaf stated that transit through the strait will now become chargeable after an initial grace period outlined in the MoU. Ghalibaf emphasized Iran’s sovereignty over the waterway alongside Oman and indicated that free passage was temporary, tied to a 60-day negotiation window.

“Transit through the Strait of Hormuz will now be chargeable,” Ghalibaf was reported as saying, underscoring that Iran would exercise its rights to impose fees for services and security provided in its territorial waters post the agreed interim period.

The developments unfold against the backdrop of the Islamabad MoU, signed in mid-June 2026, which aimed to halt military operations, reopen the strait, and set the stage for broader talks on sanctions relief, nuclear issues, and reconstruction. However, both sides have accused each other of violations, with Iran pointing to continued regional actions involving Israel and Lebanon as justification for renewed pressure.

US officials and maritime authorities have pushed back on the closure claims, with reports indicating some continued commercial traffic and warnings against disruptions to freedom of navigation.

Analysts warn that a sustained closure could spike global energy prices and complicate ongoing diplomatic efforts in Switzerland and elsewhere. No immediate independent confirmation of a total blockade was available, but ship tracking data reflects heightened caution in the region.

The situation remains fluid, with potential for further military or diplomatic repercussions as both nations navigate the fragile post-conflict framework.