Iran has once again declared the Strait of Hormuz closed to traffic, citing the persistent U.S. blockade of its ports as the immediate cause. This latest closure, announced on Saturday, April 18, 2026, follows a brief period where Iran had declared the vital waterway open. Reports indicate that Iranian forces fired upon commercial ships attempting to transit the strait during this renewed closure, adding a layer of escalating tension to an already precarious situation.
The announcement comes as negotiations aimed at securing a wider peace deal between the U.S. and Iran appear to be faltering. President Donald Trump stated his expectation of a deal "in a day or two" just hours before Iran’s latest move, claiming Iran had agreed to halt uranium enrichment. However, Iran's parliamentary speaker, Mohammad Bagher Ghalibaf, had previously disputed claims of an unconditional opening of the strait, suggesting commercial ships would need to coordinate with Iranian forces.
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Iran's declaration of the strait's closure directly links the move to the U.S. naval blockade of Iranian ports. This assertion frames the conflict as a direct response to U.S. actions, potentially positioning Iran as reactive rather than initiating further disruption. The U.S. Central Command reported turning back 21 ships to Iran since the blockade began on Monday.
The volatile situation has had profound global economic consequences. The earlier closure of the strait in March 2026 was the largest disruption to world energy supply since the 1970s energy crisis, sending Brent crude oil prices soaring past $100 per barrel and peaking at $126. This event also impacted other commodity markets, including aluminum, fertilizer, and helium.
The narrative surrounding the strait's status has been marked by confusion and conflicting statements. On Friday, Iran declared the strait open after a 10-day truce between Israel and the Lebanese militant group Hezbollah. President Trump publicly thanked Iran for this reopening, but shortly thereafter, reports emerged of Iran reimposing restrictions. Maritime tracking data indicated that despite the declared opening, few ships were moving through designated safe lanes, and some still required Iranian approval.
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This latest development also comes amid continued diplomatic efforts. Pakistani military chief Field Marshal Asim Munir recently concluded a visit to Iran aimed at securing a peace deal, though sticking points such as Iran's nuclear program and the future of the Strait of Hormuz reportedly remained unresolved. The ceasefire in Lebanon, which temporarily saw the strait declared open, is due to expire on April 22, 2026.
The conflict's origins trace back to February 28, 2026, when the U.S. and Israel launched surprise attacks on Iran, resulting in the deaths of Iran's supreme leader and other senior officials, despite ongoing diplomatic talks. The U.K. Maritime Trade Operation (UKMTO) has reported numerous incidents affecting vessels in the region, including at least 18 reports of attacks on ships operating in and around the Gulf, Strait of Hormuz, and Gulf of Oman since March 1. A tugboat was sunk, and at least 16 merchant ships were damaged, with 12 seafarers killed or missing.
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In response to Iran's actions, UK Prime Minister Sir Keir Starmer announced that his country, along with France, would lead a multinational mission to protect commercial shipping routes in the Strait of Hormuz. President Trump has maintained that the U.S. naval blockade will remain in full force until a satisfactory "transaction" with Iran is completed, warning against what he termed Iranian "blackmail."
