The US State Department has approved the sale of $500m-worth of missile system services and military support to Saudi Arabia.

The sale will have to be approved by the US Congress within a 30-day period before it is finalised.

The transaction includes the provision of technical assistance and support for Saudi Arabia's Patriot field surveillance programme (FSP), Patriot advanced capability 3 (PAC-3) FSP, and Patriot engineering services programme (ESP).

It also includes Patriot and Hawk missile system spare parts and repair and return management services and component repairs, among others.

The principal contractors for the sale are Lockheed Martin for the FSP and Raytheon Company for the ESP.

The US State Department said there are no known offset agreements proposed in connection with the potential sale.

In November last year, Saudi Arabia said it intercepted a long-range missile that targeted King Khaled International airport in the capital Riyadh.

The Houthi rebel group claimed responsibility for firing the long-range Burkan H2 ballistic missile from Yemen.

Authorities in Saudi Arabia shortly said the missile was shot down near the capital, with some fragments from the explosion landing on the airport.