President Donald Trump announced on 13 July that the United States is reinstating its naval blockade of Iranian ports and will levy a charge equivalent to 20 percent of the value of all other cargo transiting the Strait of Hormuz. In a post on his Truth Social platform, Trump said the strait “will remain OPEN, with or without Iran” and that the US would henceforth be known as “THE GUARDIAN OF THE HORMUZ STRAIT.” The US Central Command later confirmed that the blockade would resume at 16:00 Eastern Time on 14 July. Global benchmark Brent crude rose more than 4 percent on the news before paring gains.

The US position, as articulated by Trump and military officials, frames the blockade as a targeted measure that stops only Iranian ships or their customers from entering or leaving the waterway, while all other nations retain “fair and open use.” Trump argued that the US had guarded the strait for decades without compensation and that wealthy nations benefiting from secure passage should now reimburse Washington. The 20 percent fee, he said, would cover “any and all costs necessary to do the job of providing safety and security to this very volatile section of the World.” The White House did not immediately detail how the levy would be collected or enforced.

Iran’s senior military headquarters, Khatam al-Anbiya, responded by stating it would not permit the United States to “interfere in the management” of the strait. A spokesman warned that any cooperation or logistical support extended to US forces would be considered “an act of war against the sovereignty and national security of Iran,” and that if the conflict spreads, “the flames of war will engulf all the countries of the region.” The Iranian foreign ministry separately said the interim memorandum of understanding signed with the US in June had “entered a crisis phase” and that Tehran would not honour its commitments as long as Washington violated the agreement. Iran’s Revolutionary Guards have maintained that the strait is closed and that passage permits will be issued only once stability is restored.

The announcement erases the last remaining concession made to Iran under the 15 June memorandum of understanding, which had lifted an earlier US blockade and provided for toll-free commercial shipping during a 60-day negotiating window. The International Maritime Organization reiterated that there is “no legal basis through which to introduce mandatory tolls simply to transit through a strait.” US Secretary of State Marco Rubio had previously stated that no country is permitted to charge fees on an international waterway. The renewed blockade and fee proposal follow a weekend of heavy missile and drone exchanges, with Iran striking US military facilities in several Gulf states and the US hitting dozens of Iranian air-defence, radar, and missile sites.

With the interim deal effectively collapsed, the path to a permanent settlement is uncertain. The US and Iran are approaching the midpoint of the 60-day negotiation period, but diplomatic channels are now severely strained. Iran’s foreign ministry said it is talking to mediators from Qatar, Pakistan, and Oman to prevent further escalation. The US military has indicated that additional guidance for commercial mariners will be issued through formal notices, while shipping data shows transits through the strait have already fallen to their lowest level in over a month.