US Treasury Secretary Scott Bessent threatened sanctions against any country, company or person helping impose tolls on shipping through the Strait of Hormuz on May 28, 2026. He singled out Oman, a US partner and mediator in the conflict with Iran, warning that Washington would target actors involved directly or indirectly in facilitating fees.
Bessent said the United States would not tolerate a toll system in the strait. His statement addressed Iranian proposals reportedly under discussion as part of a possible arrangement with Washington. It did not establish that Oman had agreed to collect charges or that a tolling programme had begun.
The Treasury had already designated Iran’s newly created Persian Gulf Strait Authority, which Washington said collected transit fees. It also warned shipowners and other parties that paying those charges could amount to providing support to, or receiving services from, Iran’s Revolutionary Guards and might expose them to US sanctions.
The dispute concerned a passage normally used for about one-fifth of global energy supplies. Traffic and prices had been disrupted since the United States and Israel began military operations against Iran in late February. Iranian retaliation spread violence around the region and effectively restricted the strait, contributing to higher energy and fertiliser costs.
Oman played a mediation role despite itself coming under Iranian attack, according to the supplied report. President Donald Trump had appeared to threaten military action against Oman the previous day when asked about a possible short-term arrangement under which Muscat and Tehran would control the strait. The White House did not clarify whether Trump had intended to refer to Iran rather than Oman.
Bessent’s subsequent statement used economic penalties rather than direct military language, but it maintained pressure on Muscat. By warning an ally publicly, the administration sought to deter creation of a payment mechanism before it became embedded in a broader deal.
The warning arrived during a fragile truce. The United States and Iran accused each other of violations after an exchange of fire on May 28, the most serious confrontation since a ceasefire agreed in April. Indirect negotiations through mediators had continued for weeks without producing a final settlement.
The supplied evidence does not support the working claim that Oman announced it would decline participation. What it documents is an American demand backed by a sanctions threat. Whether Muscat changed policy, gave Washington private assurances or continued exploring a role was not reported. The defensible event was therefore the Treasury’s attempt to block Hormuz tolls and its explicit notice that facilitating them could carry financial consequences.
