2026伊朗-海湾危机追踪
CC
Events Archive
strikeApr 16, 2026

‘Turn around or prepare to be boarded,’ US warns ships

Summary

Senior U.S. defense officials on Thursday used a Pentagon press conference to describe how American forces are enforcing the naval blockade of Iranian ports, including the warnings issued directly to shipmasters approaching restricted waters. Defense Secretary Pete Hegseth, Joint Chiefs Chairman Dan Caine and U.S. Central Command commander General Brad Cooper said U.S. warships are repeatedly instructing vessels to turn around if they attempt to travel to or from Iranian ports, with Caine outlining the language used over open radio channels. The update comes as the war with Iran continues to disrupt global shipping and energy flows, with many ships and seafarers stranded in the Persian Gulf amid uncertainty over whether diplomacy can ease passage through the Strait of Hormuz. Why It Matters The naval blockade of Iranian ports remains one of Washington’s most consequential tools in a conflict that has already produced what energy analysts describe as the largest disruption of global oil and gas supplies on record. About 20 percent of the world’s oil and liquefied natural gas normally transits the Strait of Hormuz, making prolonged restrictions a global economic concern. For commercial shipping, the procedures described Thursday underline that enforcement is active and physical, not symbolic. Vessels attempting to challenge the blockade face boarding and seizure, influencing insurance premiums, rerouting decisions and the willingness of crews to enter the region. What to Know Thursday’s briefing offered the clearest public explanation yet of how the blockade is being carried out on the water. Caine centered his remarks on the enforcement process, offering a detailed account of the radio warnings delivered to ships. He described a junior officer on the bridge of a U.S. destroyer transmitting a standardized message. “A junior officer picks up that mic and transmits, and I quote, ‘Do not attempt to breach the blockade. Vessels will be boarded for interdiction and seizure, transiting to or from Iranian ports. Turn around or prepare to be boarded. If you do not comply with this blockade, we will use force,’” Caine said. Caine emphasized that the warning is reinforced by the physical presence of U.S. naval forces. As the message is broadcast, he said, shipmasters can “literally see, sense and feel the pressure around them” as American warships maneuver nearby. He described the operation as a “finely tuned machine.” According to Caine, the warning-and-turnaround sequence has been executed 13 times since the blockade began Monday, with vessels choosing to reverse course rather than proceed. Cooper stressed that the blockade is narrowly focused on traffic tied to Iranian ports, not an attempt to close the Strait of Hormuz altogether. The military update came as new reporting highlighted possible diplomatic maneuvering by Tehran. A Reuters report published Wednesday said a source briefed by Iranian officials indicated Iran could consider allowing ships to sail freely through the Omani side of the Strait of Hormuz without risk of attack, if a deal is reached with Washington to prevent renewed conflict. Reuters reported that the war with Iran has produced the largest-ever disruption of global oil and gas supplies because of Iran’s interruption of Hormuz traffic. Since fighting began on February 28, hundreds of tankers and other vessels, along with thousands of seafarers, have been stuck inside the Gulf. However, major uncertainties remain. The source did not say whether Iran would clear any underwater mines it may have placed in the area, or whether all ships—including those linked to Israel—would be allowed to pass freely. Reuters said the source emphasized that any safe‑passage arrangement would hinge on whether Washington is prepared to meet Tehran’s broader demands, a factor described as central to any breakthrough. What Happens Next With the ceasefire scheduled to end next week, the direction of the conflict—and the rules governing shipping near Iran—will hinge on whether talks yield an extension or hostilities resume.

Actors involved

USIsraelIran

Sources

  • Steve MollmanBy Steve Mollman

    Senior U.S. defense officials on Thursday used a Pentagon press conference to describe how American forces are enforcing the naval blockade of Iranian ports, including the warnings issued directly to shipmasters approaching restricted waters. Defense Secretary Pete Hegseth, Joint

See this event through different lenses

Compare how Western, Iranian, Israeli, Global South, and Pro-Peace perspectives frame this event.

Compare Perspectives

Community Notes

Community Notes

Loading notes...

Related events

strikeUnverifiedUSIranProxyRussia
1 source

According to Kpler data, four commodity vessels crossed the Strait of Hormuz on Monday—two exiting (one carrying petrochemicals and one empty) and two entering (a bitumen tanker and an oil tanker)—down from seven the prior day, with no very large crude carriers or liquefied natural gas tankers observed.

Yemen's Houthis stated they were imposing a naval blockade on Saudi Arabia. The UK Maritime Trade Operations agency reported receiving multiple accounts of a tanker struck by an unknown projectile in the strait, while Greek shipping company Dynacom Tankers stated that two of its vessels were hit by projectiles off Oman and a third by a drone at Russia's Novorossiysk terminal.

Location: Strait of Hormuz
strikeUnverifiedUSIsraelIranProxy
1 source

U.S. and Iranian forces have conducted daily strikes in the Strait of Hormuz region following the collapse of an interim ceasefire, according to reports. The Trump administration has stated openness to diplomacy while announcing further retaliation for attacks on U.

S. personnel, and gasoline prices have risen amid the renewed exchanges. An analyst at the Center for Strategic and International Studies described the escalations as reflecting possible miscalculations by both sides, without confirmed evidence of their long-term effects.

Location: Strait of Hormuz
strikeUnverifiedUSIsraelIran
1 source

According to reports citing unnamed sources, mediators including Qatar, Egypt, and Pakistan presented a 10-day ceasefire proposal to the United States and Iran. The proposal reportedly calls for a halt to hostilities, resumption of shipping through the Strait of Hormuz, and efforts to preserve a memorandum of understanding signed by Washington and Tehran on June 18.

The US administration is reviewing the plan while preparing for possible failure, and Israel has been placed on high alert.

Location: Iran
strikeUnverifiedIran
1 source

Vessel transits through the Strait of Hormuz totaled 53 in the week through July 20, according to Lloyd's List Intelligence data, down from 157 the previous week, with tanker and gas carrier movements falling to 30 from 90. Kpler tracking showed daily crossings declining from averages above 20 vessels before July 15 to single digits by July 16 and remaining low thereafter.

These figures followed the reported start of a U.S. blockade and related maritime restrictions announced by Iranian authorities.

Location: Strait of Hormuz