The United States has tightened security arrangements for oil tankers navigating the Strait of Hormuz, limiting protected crossings to designated periods amid renewed attacks on commercial vessels.

Under the revised arrangement, tankers are being encouraged to schedule their passage during specific daily windows when US air-defence coverage is available, rather than relying on continuous protection.

The move, as reported by USA TODAY News, follows a rise in attacks on shipping in and around the strategic waterway, heightening concerns over the safety of vessels carrying crude oil and other commodities.

The Strait of Hormuz is a critical artery for global energy supplies, and growing insecurity there has already pushed tanker freight rates to record levels, with oil prices climbing above $100 a barrel.

The latest US measure is therefore expected to add another layer of planning for shipping companies, as operators balance the need to move cargo through the region against rising security and insurance risks.