U.S. Implements Naval Blockade on Iran, Halting 13 Ships in Strait of Hormuz

The United States intensified its strategy against Iran by implementing a naval blockade during an ongoing ceasefire, with the blockade effective since Monday and focused on the Strait of Hormuz.

“From the sea and the air: How a US naval blockade works A naval blockade can be carried out by surface ships at sea and planes by air”

ABC News

Reuters reported that the enforcement began around Monday and that the blockade had already halted 13 ships, while the U.S. administration signaled optimism for a resolution but warned of increased economic pressure if negotiations did not progress.

ABC News

NPR described the White House goal as choking off Iran’s main source of revenue by cutting the country off from global maritime trade, and said the U.S. Middle East command, known as CENTCOM, would intercept all vessels going to and from Iranian ports while stating it would “not impede freedom of navigation” for ships from other Persian Gulf ports.

CNBC said the blockade of Iranian ports was “fully implemented,” with U.S. Central Command saying it “completely” halted economic trade going in and out of Iran by sea, and it tied the move to President Donald Trump’s order achieved under 36 hours.

ABC News reported that CENTCOM said the blockade had been “fully implemented” and that “U.S. forces have completely halted economic trade going into and out of Iran by sea,” while also describing the blockade as beginning Monday as reopening the Strait of Hormuz remained a sticking point in talks.

Multiple outlets also described the scale of the operation, with ABC News saying “More than 10,000 U.S. sailors, Marines, and airmen” and “over a dozen warships and dozens of aircraft” were executing the blockade, and CNBC saying it involved “more than 10,000” troops, “over a dozen Navy ships and fighter jets.”

U.S. officials and reporting outlets described the blockade as a combination of sea and air enforcement, with the U.S. military beginning a blockade of Iranian ports on Monday and using both surface ships and aircraft to monitor and interdict vessels.

ABC News explained that a naval blockade can be carried out by surface ships at sea and planes by air, and it said the blockade was “fully implemented” after the head of U.S. Central Command, Adm. Brad Cooper, told reporters late Tuesday night that “U.S. forces have completely halted economic trade going into and out of Iran by sea.”

Al Jazeera

The same ABC News report said the blockade enforcement depended on intelligence about what port a ship may have left from or is going to, because “the U.S. Navy's blockade only applies to vessels leaving or headed to Iranian ports.”

It described the operational footprint by stating that “Of the 16 U.S. Navy ships now in the Middle East, 11 are destroyers capable of intercepting vessels at sea,” and it added that each destroyer is equipped with “two SH-60 Sea Hawk helicopters” and “sophisticated Aegis radar systems capable of tracking ships at long distances.”

ABC News also quoted a warning message the destroyer crew would issue by radio, including: “The U.S. has announced a formal blockade of Iranian ports and coastal areas. This is a legal action ... If you do not comply with this blockade, we will use force.”

The report further described boarding procedures, saying Marines or other troops typically approach a vessel either by fast-rope from helicopters or by climbing from small boats, and it quoted Retired Adm. and Dean of the Center for Maritime Strategy James Foggo: “If you're looking for illegal shipments of arms or oil or anything else, you got to go on board.”

It also stated that the 31st Marine Expeditionary Unit (MEU) is aboard three amphibious ships and that VBSS—“Visit, Board, Search, and Seizure”—are legal boardings for inspections for smuggling or other unlawful activity.

While the blockade tightened maritime pressure, U.S. and Iranian officials framed the move as compatible with negotiations and as a test of whether talks could produce an end to the war.

“Credit: Jayden Brown/U”

Caspian Post

NPR said the White House wanted to increase economic pressure after “weeks of U.S. strikes have failed to persuade the country's leaders to agree to end the war on Washington's terms,” and it quoted Bryan Clark of the Hudson Institute arguing the approach was “more of a naval quarantine, because "the U.S. is only stopping traffic that's coming from Iran."”

CNBC said the U.S. blockade was accompanied by “signaling a diplomatic off-ramp for Iran,” and it quoted Brad Cooper saying the blockade was “fully implemented” and that it was achieved under 36 hours of President Donald Trump’s order.

At the same time, the U.S. signaled readiness to escalate if negotiations did not progress, with Devdiscourse saying the Pentagon, led by Chief Pete Hegseth, highlighted “readiness to launch targeted strikes on Iran's energy sector if negotiations do not progress as hoped.”

In the Reuters report carried by الخليج, Hegseth said the blockade was “the most polite way things can end” and warned that the U.S. was “ready to strike your critical dual-use infrastructure, your remaining electricity generation plants, and your energy sector.”

The same report quoted General Dan Kin saying U.S. forces were “literally ready to resume major combat operations as soon as instructions are given,” and it repeated the enforcement warning: “If you do not comply with this blockade, we will use force.”

On the Iranian side, Al Jazeera reported that Major General Ali Abdollahi said continued U.S. blockade could end the current pause in fighting, warning: “this action by the US will constitute a prelude to a violation of the ceasefire,” and it quoted Abdollahi saying “The powerful armed forces of Iran will not allow any exports or imports to continue in the area of the Persian Gulf, the Sea of Oman and the Red Sea.”

The Economic Times also quoted Iran’s senior military adviser Mohsen Rezaei warning that U.S. warships enforcing a blockade in the Strait of Hormuz “can definitely be exposed to our missiles and we can destroy them,” and it added that Rezaei said “We would take thousands of hostages and then for each hostage we would get a billion dollars.”

As the blockade moved from initial implementation to broader enforcement, reporting described both an expansion in what the U.S. would target and continuing questions about how sustainable and comprehensive the interdictions could be.

الخليج said the U.S. military broadened its blockade to include shipments suspected of smuggling and that the Navy’s updated statement said: “These ships, regardless of their location, are subject to boarding, inspection, and seizure.”

CBS News

It listed contraband categories including “weapons and weapon systems, munitions, nuclear materials, crude and refined oil, as well as iron, steel, and aluminum,” and it said the U.S. Navy stated any ship suspected of attempting to reach Iranian shores would be subject to boarding and search.

The Economic Times similarly described U.S. expansion of the shipping blockade to target a wider range of contraband, including “munitions, weapons, oil, refined products, and metals such as iron, steel, and aluminium,” and it said an advisory warned that vessels suspected of carrying such cargo to Iran may be stopped and inspected under the “belligerent right to visit and search.”

At the same time, NPR emphasized enforcement constraints, saying blockades are hard to enforce and that “it would be almost impossible [for the Navy] to keep up with that traffic volume,” given that “an average of 138 ships passed through the strait daily” before the U.S.-Iran war.

NPR also quoted Steve Dunn saying “Detection of vessels is much easier, with satellite, [planes and drones] and radar,” and it quoted Clark that the Navy would likely need “six or so destroyers in rotation” to enforce the strait blockade.

The same NPR report described how the U.S. Navy would intercept ships and force them to turn or take them to a marshaling area or an anchorage in Oman, while also saying “I don't see the U.S. mounting a scorched-earth campaign of attacking every little vessel that tries to evade the blockade.”

CNBC added that during the first 24 hours “no ships made it past the U.S. blockade,” and it said “six merchant vessels” were ordered to turn back to reenter an Iranian port on the Gulf of Oman, while Windward identified at least two vessels that made their journey through the Strait of Hormuz in the first full day under active enforcement.

Reuters and other outlets also described the blockade as focused on Iranian ports and coastal areas, with Al Jazeera and Caspian Post reporting that Iran warned the blockade could end the ceasefire and that Iran would not allow exports or imports in the Persian Gulf region, the Sea of Oman and the Red Sea.

The blockade was presented across outlets as a direct attempt to cut off Iran’s oil revenue and to impose daily economic damage while also raising global market risks.

CNBC said the blockade would cut off Tehran’s international sea trade that “powers about 90% of its economy,” and it cited Miad Maleki saying “More than 90% of Iran's $109.7 billion in annual seaborne trade transits through the Strait of Hormuz.”

CNBC

CNBC also estimated the blockade would cost Iran “approximately $435 million a day in combined economic damage,” and it described the blockade as taking effect Monday amid a “shaky two-week ceasefire.”

The same outlet said Iran had choked the Strait of Hormuz in retaliation for joint U.S.-Israeli strikes that began Feb. 28, and it warned the blockade could “upend energy flows” and “risks straining Washington's ties with countries such as China and India.”

NPR similarly framed the blockade as a move aimed at increasing economic pressure after U.S. strikes failed to persuade Iran to end the war on Washington’s terms, and it described the economic pressure tactic as finding and cutting off “something which is nonsubstitutable, something that is so essential to their economy that everything else is going to come to a halt.”

The Economic Times added that Iran halted petrochemical exports to prioritize domestic supply after Israel struck petrochemical hubs, and it said Iran’s senior adviser Mohsen Rezaei warned of hostage-taking and demanded “a billion dollars” per hostage.

It also reported that the U.S. imposed sanctions on “over two dozen individuals, companies and vessels linked to Mohammad Hossein Shamkhani,” with Treasury Secretary Scott Bessent saying the move was part of “Economic Fury” and that Treasury was “targeting regime elites like the Shamkhani family.”

Al Jazeera reported that Iran’s Major General Ali Abdollahi warned the blockade could constitute a “prelude to a violation of the ceasefire,” while the same report quoted Iran’s foreign ministry spokesman Esmaeil Baghaei saying the goal of talks would be to “fully cease the war and realise the rights of Iran” and to lift sanctions.

Finally, CNBC and CBS News both tied the blockade to the Strait of Hormuz as a critical chokepoint, with CBS News quoting CENTCOM’s Brad Cooper saying “An estimated 90% of Iran's economy is fueled by international trade by sea” and that “In less than 36 hours since the blockade was implemented, U.S. forces have completely halted economic trade going into and out of Iran by sea,” while also reporting that the war was in its seventh week and a two-week truce was set to expire Tuesday.