US Congress will be notified about a proposed $60bn weapons sale to Saudi Arabia as early as this week, a defence official has said.

The arms package, believed to be the largest in US history, includes 84 new F-15s and upgrades to a further 70 in the Saudi inventory at a cost of $30bn.

The package also includes $30bn in helicopter sales including spare parts, training simulators, long-term logistics support and munitions, according to Bloomberg.

The helicopters to be procured include 72 UH-60 Black Hawk helicopters, 70 AH-64D Longbow Apaches and 36 AH-6 Little Birds.

The Longbow is the US’s premier anti-tank helicopter, capable of firing laser-guided or all-weather radar-guided air-to-ground Hellfire missiles.

Saudi Arabia spent $36.7bn on arms and support activities from 2001 to 2008, according to the nonpartisan Congressional Research Service.