The US military will resume its maritime blockade of Iranian ports at 4 p.m. ET on July 14 under President Donald Trump's direction, US Central Command said Monday in a post on X.
US Centcom said it "will resume blockading maritime traffic entering and exiting Iranian ports" and will enforce the restrictions on vessels traveling to or from Iranian ports and coastal areas.
"The US military continues to support traffic flow through regional waters for all vessels not violating the blockade," Centcom added.
The renewed operation follows the previous blockade, which ran from April 13 to June 18. During that period, US forces redirected over 140 compliant vessels, disabled nine non-compliant ships and allowed over 50 humanitarian commercial vessels to transit, the command said.
The US-navy led Joint Maritime Information Center also issued an advisory Monday outlining the naval blockade and providing guidance for shipowners, operators and mariners.
The advisory stated that a restricted area exists due to the military blockade operations in the Gulf, Gulf of Oman, North Arabian Sea, and the Strait of Hormuz.
It said the regional maritime security threat remains "severe," with "further deliberate hostile activity likely under current conditions," following recent incidents in the Strait of Hormuz.
The advisory warned mariners to expect "sustained naval presence, increased IRGC hailing and monitoring along transit routes," as well as possible diversions and congestion near anchorage areas.
The advisory said the blockade covers Iran's entire coastline, including ports and oil terminals, and applies to all vessels regardless of flag. Unauthorized ships entering or leaving the restricted area could face interception, diversion or capture.
The JMIC added that the blockade "will not impede neutral transit passage through the Strait of Hormuz" for vessels traveling to or from non-Iranian destinations. However, US forces may still board and inspect ships to verify compliance.
It also warned that ships conducting ship-to-ship transfers to help vessels bypass the blockade could face boarding. Non-compliant vessels risk "disabling and destructive fire" if they fail to obey blockading forces.
Aircraft and vessels should avoid the designated warning area where possible, the advisory said. Ships continuing to transit should clearly communicate their intentions and maintain a 30-nautical-mile distance from US naval units to reduce the risk of misidentification.
The advisory said Iranian vessels and ships suspected of carrying contraband remain subject to visit, boarding, search and seizure. Goods intended for Iran that could support armed conflict may also be confiscated under blockade enforcement.
Operators seeking humanitarian exemptions must submit vessel and cargo details, including the International Maritime Organization number, ownership information, cargo description and bills of lading, for US Navy review. Approved ships may still face boarding and inspection, the advisory said.
US Centcom advised mariners operating near the Gulf of Oman and in the approaches to the Strait of Hormuz to monitor Notice to Mariners broadcasts and to contact US naval forces on bridge-to-bridge Channel 16.
Brent futures rose 9.50% to $83.23 per barrel, while West Texas Intermediate futures gained 9.34% to $78.08/bbl as traders assessed the renewed US blockade of Iranian ports.