Iran's Islamic Revolutionary Guards Corps (IRGC) has issued a stark warning that any military vessels approaching the Strait of Hormuz — the narrow waterway between the Persian Gulf and the Gulf of Oman through which roughly a fifth of the world's crude oil and liquefied natural gas normally flows — will be treated as a violation of the fragile two-week ceasefire between Tehran and Washington. The warning came hours after US President Donald Trump announced that the US Navy would begin blockading vessels entering or leaving the strait, and after weekend nuclear talks in Islamabad ended without an agreement.
The IRGC's naval command said in a statement that the strait is "under the control and smart management of Iran's Navy" and remains open only to non-military vessels following specific regulations. It posted a video showing ships in crosshairs, accompanied by an ominous message: "The enemy will become trapped in a deadly vortex in the strait if it makes the wrong move." Iranian state television also broadcast footage it claimed showed IRGC forces warning off a US Navy destroyer — identified as vessel number 121 — ordering it to return to the Indian Ocean under threat of being targeted. US Central Command, however, said two American destroyers, the USS Frank E. Petersen and the USS Michael Murphy, completed a minesweeping mission through the strait without incident — a claim Tehran flatly denied.
The standoff follows a breakdown in negotiations held in Islamabad on Saturday, mediated by Pakistan under Prime Minister Shehbaz Sharif and military chief Field Marshal Asim Munir. The talks, which lasted nearly 20 hours across three sessions, were led on the American side by Vice President JD Vance and on the Iranian side by Parliament Speaker Mohammad Bagher Ghalibaf. Vance said the two sides were "unable to make any headway," while Iran's Foreign Ministry acknowledged that on "two or three important issues, views were far apart." Trump later said the talks had gone "well" overall but that Iran's nuclear programme — the issue he described as the only one that "really mattered" — remained unresolved.
Trump followed the diplomatic failure with escalatory rhetoric. He said the US Navy had been instructed to intercept ships that had paid what he called "illegal tolls" to Iran, and threatened to destroy Iranian power plants and energy infrastructure if no deal was reached. "Any Iranian who fires at us, or at peaceful vessels, will be BLOWN TO HELL," he wrote on his Truth Social platform. He also claimed Iran had promised to reopen the strait as a condition of the ceasefire but had deliberately failed to do so. Iranian state media close to the IRGC noted, with some irony, that Trump's blockade threat had effectively reversed a brief 11% drop in Brent crude oil prices — to around $97 a barrel — that followed the ceasefire announcement, potentially pushing prices far higher.
The exchange of threats underscores the fragility of the ceasefire that halted US and Israeli strikes on Iran, which began on 28 February. The strait's closure since then has already contributed to a global fuel crisis, and with diplomacy stalled and military posturing escalating on both sides, the risk of miscalculation in one of the world's most strategically sensitive waterways is rising sharply. Iran's Ghalibaf said after the talks that it was now for the United States to decide whether it could "earn" Tehran's trust — a signal that, despite the breakdown, the door to negotiations has not been entirely shut.