The US military has announced that it will begin blockading all Iranian ports on Monday.

This marks the latest move to exert pressure on Tehran after marathon peace talks in Pakistan concluded without a deal.

In a statement, US Central Command (CENTCOM) said that the blockade would apply to “all maritime traffic entering and exiting Iranian ports” from 10am Eastern Time (14:00 GMT) on April 13. That includes “vessels of all nations entering or departing Iranian ports and coastal areas”, including those on the Gulf and the Gulf of Oman.

In an apparent scaling back from President Donald Trump’s earlier threat to blockade the entire strait and pursue ships paying tolls to Iran, CENTCOM said, that US forces “will not impede freedom of ⁠navigation for vessels transiting the Strait ⁠of Hormuz to and ⁠from non-Iranian ports.”

Iran has essentially taken control over the Strait of Hormuz, a vital chokepoint for the global energy market, since the US and Israel launched a war against the country on February 28. Traffic through the waterway has since slowed to a trickle, nearly paralysing about one-fifth of the world’s oil and liquefied natural gas shipments.

Iran has continued to move its own vessels through the strait, while allowing limited passage of ships from other countries. Iranian officials have discussed setting up a toll system after the fighting ends.

The US-declared blockade appears to be triggered by the failure of the talks in Pakistan’s capital, Islamabad, raising fears of renewed fighting.

Iranian officials blamed the US side for failing to reach a deal, with Minister of Foreign Affairs Abbas Araghchi saying that US negotiators shifted the “goalposts” and obstructed efforts when a memorandum of understanding was “just inches away.”

The face-to-face talks that ended early Sunday were the highest-level negotiations between the longtime rivals since the 1979 Islamic Revolution. Trump said that Tehran’s nuclear ambitions were the core reason for the talks’ failure. In comments to a news agency, he again threatened to strike civilian infrastructure if it didn’t give up its nuclear program. “In one half of a day they wouldn’t have one bridge standing, they wouldn’t have one electric generating plant standing, and they’re back in the stone ages,” Trump said

Iranian officials said that talks fell apart over two or three key issues, blaming what they called US overreach. Iranian parliament speaker, Mohammad Bagher Qalibaf, who noted progress in negotiations, said it was time for the United States “to decide whether it can gain our trust or not.”

Iran’s Foreign Minister claimed that the U.S. tanked the negotiations when they were within “inches” of an agreement, but did not provide evidence. “We encountered maximalism, shifting goalposts, and blockade,” Araghchi noted on X.

Neither Iran nor the US indicated what will happen after the ceasefire expires on April 22. Pakistani Foreign Minister Ishaq Dar said that his country will try to facilitate a new dialogue in the coming days. Iran said it was open to continuing dialogue.

Iran Calls Blockade Breach Of Ceasefire

In a statement responding to Trump’s blockade threat, Iran’s Islamic Revolutionary Guard Corps said that any approaching military vessels would be in breach of a US-Iran ceasefire, meant to be in effect until April 22, and “will be dealt with severely.”

A chorus of top-ranking Iranian officials threatened retaliation. Mohsen Rezaei, a military adviser and a former Revolutionary Guard Commander, wrote on X that the country’s armed forces had “major untouched levers” to counter a Hormuz blockade. He said that Iran would not be coerced by “tweets and imaginary plans.”

Qalibaf, who led Iran’s side in the talks, addressed Trump in a statement on his return to Iran: “If you fight, we will fight.”

Two semi-official Iranian news agencies reported that Iran’s Revolutionary Guard later said that the strait remained under Iran’s “full control” and was open for non-military vessels, but military ones would get a “forceful response.”

Zohreh Kharazmi, an Associate Professor at the University of Tehran, said that the US “is not in a position to dictate” to Iranians how to behave, or “to choose which vessels may pass.” “If this blockade becomes a contest between the resilience of the Islamic Republic and the resilience of global markets, it will not take long to see who is losing,” she said, adding that Iran “is ready for a prolonged war.”

She added that technically, the US cannot control the situation. “With Hollywood-style strategies, they cannot prevail in this battleground,” she said.