US Treasury Warns Oman of Aggressive Sanctions Over Strait of Hormuz Toll Threats

The United States Treasury Secretary Scott Bessent told Oman on Thursday, 28 May 2026, that Washington would "aggressively" target any actors involved in facilitating tolls on the Strait of Hormuz, according to multiple reports from regional and wire sources. The warning, delivered as a direct communication to Muscat, marks a notable escalation in the US posture toward countries that might assist Iran in imposinglevies on the narrow waterway through which roughly a fifth of the world's oil shipments pass.

The explicit threat of secondary sanctions against Omani entities — or any other regional actors — signals the Biden administration's successor, now under Treasury Secretary Bessent, is prepared to use the full weight of US financial power to preserve what Washington regards as the existing free-transit regime of the Strait. Oman, which shares a land border with Iran and controls the Musandam Peninsula overlooking the Hormuz narrows, has long served as a back-channel interlocutor between Washington and Tehran. Thursday's warning complicates that role.

The Warning and Its Immediate Context

According to reporting carried by Middle East Eye and confirmed by Al Jazeera's breaking news desk, Treasury Secretary Bessent stated on 28 May that Oman "should know" Washington would take aggressive action against facilitators of Hormuz tolls. A simultaneous dispatch from the US State Department's regional monitoring apparatus, cited by the Telegram channel Our Wars Today, described the warning as encompassing both direct and indirect involvement in any toll-imposition effort.

The sources do not specify whether Iran has formally announced a toll mechanism or whether the US intelligence assessment is that Tehran is in the process of developing one. What is clear is that the administration has moved from monitoring to active deterrence. Secondary sanctions — penalties applied to non-US persons or entities for dealings with sanctioned parties — remain the инструмент of choice: they carry no requirement for boots on the ground and leverage the dollar's centrality to global commerce.

Oman's Precarious Diplomatic Position

Oman has historically occupied a distinctive position in Gulf geopolitics. Under the late Sultan Qaboos and his successor, the Sultanate has cultivated a reputation for quiet diplomacy, maintaining relations with both Washington and Tehran simultaneously. Muscat hosts Oman's principal port facilities close to the Hormuz narrows, and Omani companies operate significant transshipment and logistics infrastructure in the region.

Thursday's warning puts that balancing act under direct pressure. If Washington follows through on Bessent's language, any Omani entity — state-owned enterprise, private logistics firm, or port authority — found to be enabling a toll mechanism could find itself cut off from the US financial system. That prospect is not abstract: US secondary sanctions have previously succeeded in strangling financing for targeted entities, often faster than diplomatic engagement.

The sources do not indicate how Muscat has responded to the warning. Oman's foreign ministry had not issued a public statement as of 18:00 UTC on 28 May.

The Structural Stakes of the Hormuz Transit Regime

The Strait of Hormuz is not merely a shipping corridor — it is a load-bearing piece of global energy infrastructure. Approximately 21 million barrels of oil per day move through the passage, and the economic logic of the waterway has historically overridden political competition: no major power has had an interest in genuinely closing the strait, because the resulting supply shock would be global and self-harming.

But a toll is a different proposition from closure. A levy — even a modest one — could serve multiple Iranian objectives simultaneously: generating revenue, asserting de facto jurisdiction over the passage, and creating a new friction point in US-led efforts to isolate Tehran's oil sector. If other regional states tacitly accept the toll, or fail to obstruct its collection, the precedent would represent a quiet but significant shift in the norms governing international waterways.

The US position, as articulated by Treasury, is that any toll represents a form of illegitimate coercion against international shipping. That framing — transit freedom versus coercive extraction — has a long history in international law, particularly in strait-states jurisprudence. But the enforcement mechanism remains entirely financial. Absent a naval posture that physically interdicts collection, Washington's only credible tool is sanctioning the collectors and their enablers into submission.

Forward View: Escalation Risk and Diplomatic Off-Ramps

The immediate risk is miscalculation. A public ultimatum from the US Treasury leaves little room for private negotiation: if Muscat perceives the warning as a non-negotiable demand rather than an opening gambit, it may feel compelled to demonstrate independence by failing to cooperate — or worse, by positioning itself closer to Tehran as a signal of sovereignty. Regional watchers will be watching Oman's foreign ministry statements, and any Iranian confirmation of a toll scheme, closely in the coming days.

The structural picture — a declining dollar share of global reserves, growing South-South trade in non-dollar currencies, and an Iranian economy that has survived maximum-pressure campaigns before — suggests the long-term pressure on the Hormuz free-transit norm is real. A toll scheme, if implemented and left unchallenged, would normalise a principle that Washington has a direct interest in suppressing. Thursday's warning is a statement of intent. Whether it changes behaviour will depend on the enforcement that follows.

This publication's wire coverage led with the directness of Bessent's threat language, a marked contrast to prior US statements that framed Iranian Hormuz-related activity in more ambiguous terms of "destabilisation" and "threats to navigation." The shift to explicit sanctions language suggests the administration believes the toll scenario has moved from theoretical to operational.