The United States military began a naval blockade of all Iranian ports on Monday, enforcing the measure after weekend peace talks in Islamabad ended without an agreement. The operation, announced by US Central Command, restricts maritime traffic entering or leaving Iranian ports in the Persian Gulf and the Gulf of Oman.
The blockade applies “impartially against vessels of all nations” heading to or from Iranian ports, according to a CENTCOM statement posted on X. The command said US forces “will not impede freedom of navigation for vessels transiting the Strait of Hormuz to and from non-Iranian ports.” Commercial ships were notified ahead of time and told to monitor maritime broadcasts.
President Donald Trump announced the move after talks with an Iranian delegation in Islamabad broke down over Tehran’s refusal to abandon its nuclear ambitions. Trump said the goal of the blockade is to force Iran back to the negotiating table and bring down gasoline prices by reopening the Strait of Hormuz to tanker traffic. The strait normally carries about a fifth of the world’s crude oil supply.
On social media, Trump warned that any Iranian warships that approach US vessels enforcing the blockade “will be immediately eliminated.” He claimed Iran’s navy had been “completely obliterated” and that only small attack ships remained.
The Strait of Hormuz has been largely closed to tanker traffic since the US and Israel launched strikes against Iran in late February. A two-week ceasefire had been in place, but officials say the blockade now puts that fragile truce at risk.
Iran responded sharply. Foreign Ministry spokesperson Esmail Baghaei called the blockade “revenge against the global economy,” and questioned whether disrupting world trade can achieve strategic gains. Iran’s ambassador to the UN called the blockade a “grave violation” of its sovereignty and a threat to international peace.
The Islamic Revolutionary Guard Corps warned that “no port in the Gulf and the Sea of Oman will be safe” if the blockade continues. The IRGC said security in those waters is “either for everyone or for no one.”
The blockade is expected to cut off roughly two million barrels of Iranian oil exports per day, further tightening global energy supplies. Iran had been exporting about 1.84 million barrels per day in March, according to Kpler data. Oil prices jumped around eight percent Monday, with both WTI and Brent contracts topping $100 a barrel.
Shipping traffic dropped sharply. At least two tankers approaching the strait turned around shortly after the blockade began, according to vessel tracker MarineTraffic. The UK Maritime Trade Operations agency said the blockade restricts “the entirety of the Iranian coastline, including ports and energy infrastructure.”
US officials said the Navy has about 15 ships in the region, including an aircraft carrier and 11 destroyers, that could participate in the blockade. The ceasefire is set to expire on April 22.