THAAD
© ReutersA Terminal High Altitude Area Defense (THAAD) interceptor
The US State Department approved the sale of Terminal High Altitude Area Defense (THAAD) to Saudi Arabia for estimated $15 billion the day after Saudi Arabia agreed to buy Russian S-400 air defense system.

The Pentagon's Defense Security Cooperation Agency "delivered the required certification notifying Congress of this possible sale" on Friday, the DSCA said in a statement.

The Saudi government has requested 44 THAAD launchers, 360 Interceptor missiles, 16 Fire Control and Communications Mobile Tactical Station Groups and seven AN/TPY-2 THAAD radars, according to the DSCA.

"This proposed sale will support the foreign policy and national security objectives of the United States by improving the security of a friendly country. 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 agency said.

"This notice of a potential sale is required by law and does not mean the sale has been concluded," the DSCA added.