President Trump’s new blockade in the Strait of Hormuz, during which the U.S. military will block Iranian ports and stop some ships looking to enter the key waterway, took effect Monday as talks with Iran faltered over the weekend.

The blockade began at 10 a.m. after 21 hours of peace talks over the weekend in Pakistan ended without a breakthrough. 

As the blockade appeared to take effect, Trump warned that Iran’s small attack boats would be “ELIMINATED” if they came near U.S. Navy ships. 

“Iran’s Navy is laying at the bottom of the sea, completely obliterated – 158 ships. What we have not hit are their small number of, what they call, ‘fast attack ships,’ because we did not consider them much of a threat. Warning: If any of these ships come anywhere close to our BLOCKADE, they will be immediately ELIMINATED, using the same system of kill that we use against the drug dealers on boats at Sea,” the president said in a Monday post on Truth Social. 

Iran appeared unwilling to back down from Trump’s threats, with the country’s acting defense minister saying Monday that Tehran is prepared for “any scenario.” Brigadier General Majid Ibn Reza also warned that any aggression against Iran would result in a “harsh and decisive response,” and that his country’s forces are on “maximum combat alert,” according to remarks broadcast on Iran’s state-run television.

And Alaeddin Boroujerdi, a member of Iran’s Foreign Policy and National Security Committee, threatened that any U.S. Navy ships attempting to block Iran’s ports will be “sent to the bottom of the sea,” Iran’s state-run Press TV reported.

Trump’s move seeks to exert economic pressure on Iran — and its allies, like China, that rely on its oil exports — after a nearly six-week U.S.-Israeli bombing campaign that has sent oil and gas prices soaring but has not prompted Tehran to surrender, frustrating the president.

U.S. Central Command, which oversees troops in the Middle East, is taking the lead on the blockade, which it said will be “enforced impartially against vessels of all nations” and would allow ships traveling between non-Iranian ports to still enter the Strait of Hormuz.

Trump on Sunday said he had instructed the Navy “to seek and interdict every vessel in International Waters that has paid a toll to Iran.”

The U.K. Maritime Trade Operations (UKMTO), which is affiliated with Britain’s Royal Navy, said in an advisory to mariners that restrictions encompass the entire Iranian coastline, which includes energy infrastructure and ports. 

“Transit passage through the Strait of Hormuz to or from non-Iranian destinations is not reported to be impeded by these measures; however, vessels may encounter military presence, directed communications, or right-of-visit procedures during passage,” the UKMTO said in the advisory. 

“Neutral vessels currently within Iranian ports have been granted a limited grace period to depart, as will be specified in the NTM,” the organization said. “All other threat, maritime security and navigation assessments remain extant as outlined in the latest JMIC advisory products.” 

Iran halted traffic in the Strait of Hormuz shortly after the U.S. and Israel attacked the country on Feb. 28, causing a global energy crisis, as one-fifth of the world’s crude oil flows through the shipping lane in times of peace.  

The U.S. and Iran last week came to a two-week ceasefire, with Tehran agreeing to open the strait, but Israel’s strikes in Lebanon caused the regime to once again close the waterway. 

The clock is now ticking on the ceasefire, with talks seemingly stalled after a marathon Saturday of negotiations, mediated by Pakistan and held in its capital Islamabad.

Vice President Vance said afterward that no progress was made toward a peace agreement, and that Iran refused to make an “affirmative commitment that they will not seek a nuclear weapon” or “seek the tools that would enable them to quickly achieve a nuclear weapon,” a red line for the Trump administration.

Trump has left open the possibility of a deal, while regional mediators are reportedly scrambling to continue negotiations.

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