Iran has notified members of the International Maritime Organization that vessels it considers "non-hostile" may transit the Strait of Hormuz if they coordinate with Iranian authorities, according to a letter that has been circulated among IMO members.
In that communication, Iran's foreign ministry said Tehran had "taken necessary and proportionate measures to prevent the aggressors and their supporters from exploiting the Strait of Hormuz to advance hostile operations against Iran." The letter, which was distributed to IMO member states, added that vessels linked to the United States and Israel, together with "other participants in the aggression," do not qualify for innocent or non-hostile passage.
"Non-hostile vessels" may transit the Strait of Hormuz if they coordinate with Iranian authorities, the letter said.
The letter arrived amid a situation that has all but halted shipments of around one-fifth of the world's oil and liquefied natural gas through the Strait of Hormuz, a development the communication said has caused oil supply disruption.
The IMO is the London-based U.N. agency tasked with regulating the safety and security of international shipping and preventing pollution from ships. It comprises 176 member states and is responsible for coordinating information among its members on navigational safety and maritime security matters.
Those receiving the Iranian letter were told Tehran had implemented measures it described as necessary and proportionate to stop what it characterizes as attempts by aggressors and their supporters to use the strait for hostile operations. The letter explicitly excluded ships associated with the United States and Israel, and others identified as participants in the aggression, from qualifying for innocent or non-hostile passage.
The report carrying the contents of the letter could not be immediately verified. The information in the circulated letter and the reference to halted shipments through the strait were presented as the basis for Iran's stated navigation guidance to IMO members.
Given the letter's wording, commercial shippers, energy market participants and authorities charged with maritime safety are likely to monitor responses and practical consequences of the guidance closely. The communication underscores how measures taken by a coastal state and the classification of vessels can directly affect transit through a major energy export route.