The U.S. blockade of the Strait of Hormuz was supposed to start at 10am U.S. Eastern time on April 13, but as yet there are no reports of it going into effect, nor its form or extent. The New York Times reported around 4pm U.S. Eastern time on April 13 that a U.S. military official said the blockade was in effect, without providing additional details.

President Donald Trump, announcing the blockade on April 12, said the U.S. Navy would block “any and all ships trying to enter, or leave, the Strait of Hormuz.” But he was almost immediately contradicted by his own military, which announced a more targeted blockade, according to the Guardian.

The U.S. Central Command (Centcom) said the blockade would be confined to vessels transiting through Iranian ports, and that it would permit passage of ships headed to ports belonging to the U.S.’s Gulf allies.

Initially Centcom said the blockade would apply to the Persian Gulf and the Gulf of Oman, which are connected by the 20-mile-wide Strait of Hormuz, but later added more confusion by sending a note to seafarers saying the blockade would only be enforced in waters east of the strait of Hormuz, according to Reuters.

Meanwhile several Nato allies said on April 13 that they would not get involved in the blockade, and would intervene only once the war ends. “We’re not supporting the blockade,” British prime minister Keir Starmer told the BBC. Germany, Spain, Italy, Poland, and Greece have all refused to send naval forces to support the blockade.

However, France’s President, Emmanuel Macron, said in a post on X on April 13 that France will organize a conference with Britain and other countries to create a multinational mission to restore navigation in the strait.