The Foreign Military Sales division of the US State Department has approved the possible sale of up to $15bn-worth of military equipment including a terminal high-altitude area defence (THAAD) system to Saudi Arabia..

The state department approved the deal on 6 October. The sale still needs US Congress approval before being finalised.

According to the Defense Security Cooperation Agency, Saudi Arabia has requested the acquisition of 44 THAAD launchers, 360 THAAD interceptor missiles, 16 THAAD fire control and communications mobile tactical station group, and seven AN/TPY-2 THAAD radars.

“This sale furthers US national security and foreign policy interests, and supports the long-term security of Saudi Arabia and the Gulf region in the face of Iranian and other regional threats,” the Pentagon said in a statement.

A day earlier, the kingdom also agreed to buy an undetermined number of Russian-made S-400 surface-to-air missile systems, along with the Kornet-EM system, TOS-1A, the AGS-30 and the Kalashnikov AK-103.

The agreement with the Russian firm was understood to be “based on the assurance … to transfer the technology and localise the manufacturing and sustainment of these armament systems in the Kingdom.”