According to a maritime security advisory issued by the Joint Maritime Information Center (JMIC) on October 28 (Wednesday), the United States is imposing a blockade on all Iranian ports and coastlines. The measure applies to all vessels, regardless of flag or ownership.

The advisory is numbered JMIC 016-26 and includes a notice from the Naval Cooperation and Guidance for Shipping (NAVCENT NCAGS) of U.S. Naval Forces Central Command. The advisory covers the Persian Gulf, the Strait of Hormuz, the Gulf of Oman, and the Arabian Sea, and sets the threat level in the region as “SEVERE.”

The U.S. side stated in the notice that the blockade is a response to what it calls “Iran’s continued aggressive actions and Iran’s unlawful attempts to control the Strait of Hormuz in violation of international law.”

In addition, according to the advisory, neutral vessels may still be intercepted. This applies to vessels carrying neutral cargo or sailing in ballast between neutral ports between the Gulf of Oman and the Strait of Hormuz. Such vessels may be queried, boarded, and searched so that U.S. forces can confirm their intentions in relation to the blockade. Citing the current geopolitical situation, the advisory urges vessels that do not need to transit the area to stay away from it in order to avoid unnecessary delays to their voyages.

The advisory requires neutral vessels to maintain a continuous listening watch on VHF Channel 16 (VHF CH16) and to comply with all instructions from U.S. forces. Vessels must be ready at all times to alter course or stop as instructed, including coming to a complete stop.

Vessels must have the following documents ready for inspection upon request (as applicable):

- Port and customs clearance documents from the last port of call

- Bill of lading (if carrying cargo)

- Ship registration certificate

- A letter of authorization signed and stamped by the agent at the next port of call (email not accepted)

- Receipts or signed contracts for stores, bunkers, spare parts, repairs and/or crew changes at the next port of call

- Confirmation of wharf, port, or berth booking at the next port of call

All documents must be signed or stamped and provided in PDF format. The advisory also recommends that vessels transiting the area allow extra transit time.