UN maritime agency rejects legal basis for Hormuz transit tolls

The International Maritime Organization said Monday that mandatory tolls for ships crossing the Strait of Hormuz have no legal basis, placing the United Nations maritime agency at odds with President Donald Trump’s demand for payments tied to cargo moving through the waterway. Trump said the U.S. military would protect traffic through Hormuz, but called for reimbursement equal to 20% of the value of all cargo transported through the strait.

The dispute adds a legal and diplomatic dimension to an already strained security situation in one of the world’s most sensitive shipping corridors. The strait is used for international navigation, and the IMO said it opposes fees charged merely for passage through such waterways.

“We have always been consistent on our stance on fees,” an IMO spokesperson said, adding that the agency stands against charging vessels to pass through straits used for international navigation. The spokesperson said there is no legal route to impose compulsory tolls solely for transit through a strait.

Trump said Monday that the Strait of Hormuz was open and would remain open “with or without Iran.” He also said the U.S. was reinstating what he called the Iranian blockade, describing it as a measure aimed only at Iranian ships or customers entering or leaving, while permitting other countries to use the strait.

Fee proposals meet legal objections

Iran has previously demanded tolls from vessels seeking safe passage through Hormuz. Under a memorandum of understanding signed with the U.S. on June 17, Tehran agreed not to charge such a toll for 60 days.

James Kraska, an international maritime law expert at the U.S. Naval War College, said tolls for transit through Hormuz are contrary to international law. Kraska said ships have an unimpeded right to transit the strait.

The legal issue turns on the treatment of straits used for international navigation. Such passages are subject to rules designed to preserve movement between areas of the high seas or exclusive economic zones. A transit toll would attach a charge to passage itself, rather than to a service voluntarily purchased by a ship operator.

Nordic American Tankers Chief Executive Herbjorn Hansson told CNBC that he viewed Trump’s proposed 20% charge as unrealistic. Hansson said Iran and the U.S. would need to agree on how the strait is administered, and said countries outside the Strait of Hormuz were also being affected by the dispute.

Shipping routes under pressure

The security situation in Hormuz has worsened after Iran attacked multiple commercial vessels crossing the strait over the past week, according to CNBC. Tehran has demanded that vessels use a northern route through Iranian territorial waters, while the U.S. Navy has been assisting ships through a southern corridor along Oman’s coast.

The U.S. has carried out multiple rounds of airstrikes against Iran in response to the attacks on shipping, according to CNBC. Tehran has responded by firing on U.S. allies in the Gulf.

Kraska said Iran cannot unilaterally change traffic routes through Hormuz under the Convention on the International Maritime Organization and the International Convention for the Safety of Life at Sea. He said Iran has a duty under those treaties to comply with the established traffic separation scheme through the strait.

For shipping companies, the contest over fees and routing raises operational questions about insurance, vessel scheduling and access to naval protection. For governments, the dispute tests how far states can go in conditioning passage through a strategic waterway while remaining within maritime law.

This story draws on original reporting from CNBC.