Iran has introduced new rules for ships passing through the Strait of Hormuz, tightening control over one of the world’s most vital energy routes amid rising tensions with the United States.

The new mechanism requires vessels seeking to transit the strait to first receive an email outlining regulations from an address linked to Iran’s maritime authorities, according to state media reports Tuesday. Ships must comply with the framework before being granted permission to pass through the waterway.

The move signals a stricter approach by Tehran toward maritime traffic in the narrow passage, through which a significant portion of global oil shipments flows.

Tensions have escalated since the outbreak of the recent U.S.-Israeli conflict with Iran, prompting competing measures over access to the strategic corridor. Iranian officials have said vessels must follow designated routes and obtain prior authorization to transit the strait.

In response, the United States has deployed naval forces in the region to support commercial shipping and maintain freedom of navigation.

Meanwhile, the Islamic Revolutionary Guard Corps (IRGC) issued a warning Tuesday, saying it would respond firmly to any ships deviating from routes approved by Iran.

"We warn all vessels planning to transit the Strait of Hormuz that the only safe passage is the corridor previously announced by Iran," the IRGC navy said in a statement carried by state television. "Any diversion of ships to other routes is dangerous and will result in a firm response."

The warning came as Washington stepped up efforts to facilitate commercial shipping through the waterway, which Iran had earlier closed following the escalation in hostilities.