US President Donald Trump announced on Sunday that the US Navy would immediately begin blockading the Strait of Hormuz, ordering the interception of any vessel that has paid a toll to Iran to transit the waterway. The move came within hours of direct peace talks between Washington and Tehran collapsing in Islamabad after roughly 21 hours of negotiations, with the nuclear dispute proving the unbridgeable divide.
"Effective immediately, the United States Navy will begin the process of blockading any and all ships trying to enter, or leave, the Strait of Hormuz," Trump wrote on Truth Social. He also warned that any vessel paying what he called Iran's "illegal" transit tolls would lose safe passage on the high seas, and that unnamed allied nations would participate in the maritime siege. Trump added that US forces were "locked and loaded" to "finish up" Iran at an "appropriate moment," language that signals a potential further military escalation.
The Strait of Hormuz — the narrow waterway between Iran, Oman and the United Arab Emirates — is the world's most critical energy chokepoint, through which roughly 20% of globally traded oil and liquefied natural gas normally passes. The strait has been largely closed since February 28, when the United States and Israel launched an air campaign against Iran. Iran's Islamic Revolutionary Guard Corps subsequently banned unauthorised passage, carried out at least 21 confirmed attacks on merchant vessels, reportedly laid sea mines, and imposed a toll of one dollar per barrel of oil carried, payable in cryptocurrency. More than 600 vessels remain stranded in the Gulf region, and an estimated 20,000 mariners are trapped, according to the International Maritime Organization. Brent crude prices surged between 10% and 13% in the early weeks of the crisis.
The Islamabad talks, brokered by Pakistan and led on the US side by Vice President JD Vance alongside envoys Steve Witkoff and Jared Kushner, were the highest-level direct negotiations since the conflict began. Trump acknowledged that "most points were agreed" but said the two sides failed on "the only point that really mattered" — Iran's nuclear programme. Vance said Washington requires an unambiguous commitment that Tehran will not pursue nuclear weapons or the technical means to rapidly build one. Iran's parliament speaker Mohammad Bagher Qalibaf, who led the Iranian delegation, said it was time for the US to decide "whether it can gain our trust or not." Iranian officials described the atmosphere as one of "mistrust" and accused Washington of overreach, while reiterating that Iran has the right to civilian nuclear energy but does not seek weapons. Iran has offered written commitments on this point before, including in the landmark 2015 nuclear deal, though experts note its enriched uranium stockpile is technically only a short step from weapons-grade material.
Why this matters: The collapse of the Islamabad talks and the imposition of a formal US naval blockade mark a dramatic new phase in a conflict that has already killed at least 3,000 people in Iran and thousands more across Lebanon and other parts of the Middle East, according to available figures. A US-enforced blockade layered on top of Iran's existing closure could tighten the stranglehold on global energy markets at a moment when analysts warn oil prices could breach $100 per barrel. Pakistani Foreign Minister Ishaq Dar urged all parties to uphold the existing two-week ceasefire, which is set to expire on April 22, and said Islamabad would seek to facilitate a new round of dialogue. Whether that window remains open — or whether the blockade announcement forecloses it — may determine whether the conflict widens further.