US warns Oman of sanctions over Iran's $2M Strait of Hormuz toll

The Trump administration threatened to sanction Oman if it helps Iran collect shipping tolls in the Strait of Hormuz, escalating a dispute that risks disrupting the flow of about 20% of the world's oil.

US Treasury Secretary Scott Bessent said Thursday that Washington will "aggressively" target any actors involved in facilitating tolls through the strategic waterway, where Iran's newly established Persian Gulf Strait Authority (PGSA) has begun charging commercial vessels up to $2 million per ship for safe passage.

"Oman, in particular, should know that the US Treasury will aggressively target any actors involved — directly or indirectly — in facilitating tolls for the Strait and any willing partners will be penalized," Bessent said in a social media post. "All nations should reject outright any efforts by Iran to disrupt the free flow of commerce."

The warning came less than 24 hours after President Donald Trump told reporters that Oman would "behave just like everybody else, or we will have to blow them up." The unusually aggressive posture toward a close Gulf ally reflects the administration's red line on the waterway, through which roughly 20 million barrels of crude and petroleum products passed daily before the conflict.

Iran formally established the PGSA under the Islamic Revolutionary Guard Corps, requiring commercial vessels to disclose ownership details, cargo and crew manifests, and pay tolls for transit. Sen. Tom Cotton (R., Ark.) separately urged Bessent in a letter to sanction any country or entity enabling the authority, warning that "every dollar collected directly finances a sanctioned terrorist entity."

Oil at the Center of the Standoff

The toll dispute compounds already elevated tensions since the US and Israel began strikes against Iran on Feb. 28. Iran responded by closing the strait and claiming sovereignty over it, sending crude prices soaring as energy markets priced in supply disruption risk. Before the conflict, about 20% of global oil consumption transited the waterway, making it the world's most important energy chokepoint.

The last time a major strait faced a coordinated tolling threat was during the 2019 tanker attacks in the Gulf of Oman, when insurance premiums for vessels transiting the region surged tenfold within weeks. Brent crude spiked about 15% during that episode before stabilizing after diplomatic intervention.

Iran's deputy secretary of the Supreme National Security Council, Ali Bagheri Kani, said Thursday that Tehran "will not allow Hormuz to be a source of insecurity for the country" and seeks to "establish a just order that negates hegemony and domination." The US and Iran have been indirectly negotiating a comprehensive end to the war, with control over the strait emerging as a central point of disagreement.

Market Implications

For energy markets, the standoff introduces a new layer of geopolitical risk premium. Options skew for Brent crude has widened as traders hedge against further supply disruption, while shipping costs for tankers transiting the region have risen. Defense sector stocks have also gained as investors price in the possibility of military escalation to secure the waterway.

The US Treasury's threat to sanction Oman — a key US ally known for its neutrality and mediation in regional crises — signals that Washington views any compromise on strait governance as unacceptable. With no resolution in sight and both sides hardening their positions, the risk of prolonged disruption to one of the world's most vital energy arteries remains elevated.

This article is for informational purposes only and does not constitute investment advice.