WASHINGTON, United States — President Donald Trump said US forces would destroy any Iranian "fast attack ships" that approach the American naval blockade of Iranian ports that came into effect on Monday.

 

"Warning: If any of these ships come anywhere close to our BLOCKADE, they will be immediately ELIMINATED," Trump said on his Truth Social network, adding that the rest of Iran's navy had been "completely obliterated."

 

The US military would be "using the same system of kill that we use against the drug dealers on boats at Sea," the president said, referring to air strikes on alleged narcotics boats off the coast of Venezuela.

 

The US military said it would begin a blockade of all Iranian ports Monday, after talks between the warring sides in Pakistan collapsed, and despite the Iranian military warning that it would treat any such action as an act of piracy.

 

Trump had announced on social media he would blockade the strategic Strait of Hormuz trade route that he has been demanding Tehran fully re-open, after Vice President JD Vance left negotiations with an Iranian delegation in Islamabad.

 

The US military said the blockade would begin at 1400 GMT, and apply to all ships leaving or seeking to dock at Iranian ports on either side of the key waterway.

 

Oil prices surged back above $100 a barrel and stocks mostly fell Monday as a US blockade of Iranian ports went into effect, ratcheting up fears for Middle East energy supplies.

 

The resurgent geopolitical tensions come after ceasefire talks between Washington and Iran broke down over the weekend, dousing hopes for a lasting end to a war that has threatened economies worldwide.

 

Traders say the prospect of widespread inflation from spiking oil prices and supply disruptions has also put a focus on corporate earnings, with a range of blue chips this week starting to report first-quarter results.

 

"The blockade will be enforced impartially against vessels of all nations entering or departing Iranian ports and coastal areas, including all Iranian ports on the Arabian Gulf and Gulf of Oman," US Central Command said in a statement, adding it would begin at 1400 GMT on Monday.

 

US forces would not impede vessels transiting the Strait of Hormuz to and from non-Iranian ports, it added.

 

Trump on his Truth Social platform confirmed the US military's statement, a more limited operation than envisaged in his earlier post that asserted all ships trying to enter or exit the strait would be blocked.

 

Iran's Revolutionary Guards had warned before the US military announcement that they had full control of traffic through Hormuz and would trap any challenger "in a deadly vortex".

 

In his lengthy social media post, Trump said on Sunday his goal was to clear the strait of mines and reopen it to all shipping, but that Iran must not be allowed to profit from controlling the waterway.

 

"Effective immediately, the United States Navy, the Finest in the World, will begin the process of BLOCKADING any and all Ships trying to enter, or leave, the Strait of Hormuz," Trump said. "Any Iranian who fires at us, or at peaceful vessels, will be BLOWN TO HELL!"

 

After the highest-level US-Iran talks since the 1979 Islamic Revolution failed to deliver a deal, Iranian foreign ministry Abbas Araghchi blamed "maximalism, shifting goalposts, and (a) blockade" that prevented an agreement he said they were "just inches away from".

 

Trump told reporters on Sunday he was ambivalent on the prospect of talks continuing with Iran.

 

"I don't care if they come back or not. If they don't come back, I'm fine," he said.