The MarineTraffic app on a smartphone shows numerous ship beacons near the Strait of Hormuz with a satellite view in the background, April 8, 2026 in Creteil, France.
Samuel Boivin | Null Photo | Getty Images
The United States said on Monday it had begun blocking ships from leaving Iranian ports in the Strait of Hormuz, in a bid to ratchet up pressure on Iran to reopen a vital oil route after peace talks broke down.
After the 10 a.m. ET deadline for the blockade to take effect, President Donald Trump warned Iranian “fast attack vessels” to stay away from U.S. forces enforcing the blockade.
“If any of these ships come close to our blockade, they will be quickly eliminated using the same killing system we use against drug traffickers on boats at sea,” Trump wrote on Truth Social. “It’s quick and brutal.”
A White House official confirmed to CNBC that the lockdown was in effect.
President Trump on Sunday blasted Iran in a social media post, accusing Tehran of “global usurpation” by refusing to abandon its nuclear ambitions and continuing to suppress traffic in the Iranian Strait.
President Trump said the U.S. blockade is scheduled to begin at 10 a.m. ET on Monday and will apply to “any vessel attempting to enter or exit the Strait of Hormuz.”
U.S. Central Command later added a warning that U.S. forces “will not impede the freedom of navigation of ships transiting the Strait of Hormuz to or from ports other than Iran.”
“The blockade will be enforced equitably against ships of all countries entering and exiting Iranian ports and coastal areas, including all Iranian ports in the Arabian Gulf and the Gulf of Oman,” the Central News Agency specified.
Ahead of the lockdown, U.S. stocks fell and oil prices soared.
In a post on Truth Social, President Trump said other countries would be “involved” in the lockdown. But some U.S. allies, including NATO members Britain and France, have already declined to join the effort.
Iranian officials reacted defiantly, warning that a U.S. economic blockade would only increase global energy prices.
“Enjoy the current numbers at the pump. The so-called ‘lockdown’ will soon make you nostalgic for $4-5 gas,” Iranian Parliament Speaker Mohammad Bagher Ghalibaf said in Sunday’s X-Post.
The fragile cease-fire agreement between the United States and Iran has not been formally abandoned, but there are serious rifts, with each side accusing the other of violating cease-fire terms.
The ceasefire was brokered last week after President Trump declared an ultimatum that if a deal was not reached by Tuesday night, Iran’s “entire civilization would be destroyed.”
U.S. negotiators, including Vice President J.D. Vance, flew to Islamabad over the weekend for peace talks with Iran, raising hopes that a deal to end the war is imminent.
But Vance said early Sunday that the U.S. delegation would return home without a deal. After 21 hours of negotiations, Iran still refused to agree not to develop or seek nuclear weapons, Vance said.
This is developing news. Please check back for the latest information.
