Iran on June 26 reasserted its right to control shipping in the Strait of Hormuz and warned Gulf states against aligning with the United States. This came a day after a ship near Oman was attacked, highlighting the instability of a preliminary deal to end the Iran war. Tehran called a joint statement by the U.S. and six Gulf states, which rejected Iran's insistence on charging tolls for transit, "interventionist, irresponsible and provocative." Deputy Foreign Minister Kazem Gharibabadi stated on X that "Safe passage through the Strait of Hormuz cannot be guaranteed under ambiguous arrangements, parallel routes or decision-making that does not take Iran’s role as a coastal state into account."

Iranian state television reported that three foreign tankers attempting "unauthorised passage" through the strait were turned back after warnings from the Islamic Revolutionary Guard Corps. The U.S. and Gulf Cooperation Council (GCC) called for "free, unconditional, and unrestricted navigation" in the strait without tolls or "attempts to assert control." The GCC also stated that a lasting peace must address Iran’s ballistic missiles, drones, and support for proxy groups. Iran's Foreign Ministry countered that the U.S. military presence in the Gulf was the cause of regional insecurity and division, suggesting the strait should be governed by Iran and Oman in accordance with the interim deal.

Oil prices dropped by more than 3% on June 26, heading for steep weekly losses, despite conflicting interpretations of last week's interim deal between Iran and the U.S. and a reduction in traffic through the strait, which typically handles a fifth of global oil and liquefied natural gas supplies. Two U.S. officials claimed Iran fired on a ship, although Iran's Persian Gulf Strait Authority stated that passage through unauthorized routes would be the responsibility of the owner, operator, and vessel commander. The International Maritime Organization (IMO) temporarily paused its operation to escort ships through the Strait of Hormuz after the incident near Oman. U.S. Secretary of State Marco Rubio, finishing a tour of the Gulf to reassure allies about the interim pact, warned on June 25 that if Iran threatened or blocked ships in the strait, "we’re going to have a problem."

Taiwan's Evergreen Marine reported that its Singapore-flagged ship, Ever Lovely, was struck by an "unknown object" near Oman on June 25 while on a route recommended by the British navy agency UKMTO. No one was injured, and the ship later continued its journey out of the strait. The IMO and Oman had announced a new southern route through the strait earlier in the week to evacuate hundreds of ships stranded by the war, a move that angered Tehran. Saudi Aramco resumed crude loadings on June 26 at its Ras Tanura terminal in the Gulf, the world's largest oil port, after a nearly four-month halt.

Iran took effective control of the waterway after U.S.-Israeli strikes on Iran on February 28 initiated the war, disrupting oil flows and rattling global energy markets and the broader economy. A memorandum of understanding signed last week by Tehran and Washington to extend their ceasefire stipulates that commercial ships may transit the strait free of charge for the next 60 days, during which Iran and Oman are to discuss future administration and maritime services in the strait. However, the provision does not specify who has direct authority over the waterway during this 60-day negotiation period.