The State Department approved a possible $15 billion sale of a Lockheed Martin [LMT] Terminal High Altitude Area Defense (THAAD) missile defense system to Saudi Arabia, the Defense Security Cooperation Agency (DSCA) said Oct. 6.

DSCA notified Congress of the sale on the same day.

Saudi Arabia requested 44 THAAD launchers, 360 interceptor missiles, 16 THAAD Fire Control and Communications Mobile Tactical Station Group, and seven Raytheon [RTN]-made AN/TPY-2 radars.

The sale would also include maintenance equipment, 43 trucks to move the systems, electrical power units, trailers, communications equipment, technical documentation, and training equipment.

A State Department official told sister publication Defense Daily that this sale is part of the larger $110 billion defense sale announced during the President’s trip to Saudi Arabia in May. The White House previously said once finalized the overall weapons sale would likely be the largest single deal made with an ally.

DSCA said the sale boosts the long-term security of Saudi Arabia and the Gulf region against Iran and regional threats. The agency said this sale “will substantially increase Saudi Arabia’s capability to defend itself against the growing ballistic missile threat in the region.”

The agency also noted THAAD will add an upper-tier to Saudi Arabia’s layered missile defense architecture and support modernization of the country’s air defense force.

Lockheed Martin said in a statement to sister publication Defense Daily that it is supporting the U.S. and Saudi governments as they discuss this possible procurement.

“This is a major endorsement of our missile defense capabilities, and we look forward to supporting the U.S. and Saudi governments as they continue discussions,” the company said.

This is the first sale of THAAD to Saudi Arabia. The United Arab Emirates, Saudi Arabia’s neighbor, was the first foreign buyer of THAAD in 2011 and began fielding the system in 2016. In 2012 Qatar first expressed formal interest in the system as well.

Earlier in 2017, South Korea deployed a U.S.-provided THAAD battery aimed at protecting it against some North Korean ballistic missile threats. The U.S. has also deployed a THAAD system to Guam, also aimed at North Korean threats. THAAD first intercepted an intermediate-range ballistic missile (IRBM) target in July.

The primary contractors for this sale are Lockheed Martin and Raytheon.

The announcement said implementing this sale would require posting 111 contractor and 18 U.S. government personnel to Saudi Arabia for an extended period.