Iran declares Strait of Hormuz closed as US prepares to resume naval blockade

Iran's Islamic Revolutionary Guard Corps said it had closed the Strait of Hormuz after firing a warning shot at a vessel it claimed was using an unauthorized route. The closure follows a series of missile and drone attacks on commercial ships in the waterway, including two incidents reported by the UK Maritime Trade Operations where tankers were hit by projectiles.

The United States' Central Command announced that a naval blockade of ships entering and leaving Iranian ports will resume at 4 p.m. ET. President Donald Trump said the United States would act as the "guardian" of the strait and suggested a 20 % charge on cargo value to cover security costs, though details on implementation were not provided.

The Joint Maritime Information Center, overseen by the U.S. Navy, maintains that the southern route along the Omani coast remains open for two-way traffic, a position contested by Tehran, which argues that the presence of U.S. forces makes passage impossible.

International bodies have reiterated that the strait is an international waterway. The International Maritime Organization stated that passage should remain free of tolls and charges under international law, and the United Kingdom called for the strait to reopen without fees.

Oil markets reacted sharply, with Brent crude rising over 4 % to about $87 a barrel and U.S. WTI crude gaining roughly 3.5 %.

In related developments, Israeli Prime Minister Benjamin Netanyahu warned Iran of a stronger response if Israel is attacked, and Tehran's foreign ministry condemned the United Kingdom's designation of the IRGC as a security threat, calling the move a "provocative act" that violates international law.