US Chairman of the Joint Chiefs of Staff General Dan Caine speaks as a map of the Strait of Hormuz is displayed during a press briefing at the Pentagon in Washington, DC, on April 16, 2026.
Saul Loeb | Afp | Getty Images
The U.S. Navy has turned back 13 ships since its blockade of Iranian ports in the Persian Gulf and the Gulf of Oman began more than 24 hours earlier, the Pentagon said Thursday.
President Donald Trump announced the blockade on Sunday after complaining that Tehran has not appeared to reopen the Strait of Hormuz, one of his conditions for agreeing to the fragile two-week ceasefire that is currently in effect.
The attempt to ratchet pressure on Iran began after an initial round of U.S.-Iran peace talks failed over the weekend. The U.S. on Wednesday continued to signal optimism about the prospect of reaching a diplomatic end to the war, which began Feb. 28.
“The U.S. action is a blockade of Iran’s ports and coastline, not a blockade of the Strait of Hormuz,” Joint Chiefs of Staff Chairman Dan Caine noted at a press briefing Thursday morning.
Trump had declared on Sunday that the U.S. would blockade the strait itself, before U.S. Central Command later clarified the scope of enforcement.
It “applies to all ships, regardless of nationality, heading into or from Iranian ports,” Caine specified Thursday.
U.S. forces are also actively pursuing “any Iranian flagged vessel or any vessel attempting to provide material support to Iran” in other areas — including lawbreaking ships known as “dark fleet” vessels, Caine said.
Caine said that when blockaded ships approach, the Navy transmits a warning: “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.”
“It’s a finely tuned machine rehearsed multiple times and executed now 13 times since the blockade has begun,” Caine said.
Those 13 ships “have made the wise choice of turning around and as we continue to hold this blockade,” he said, adding that the military hasn’t had to board any ships yet.
