U.S. defense giant Lockheed Martin has received a $1.48 billion contract modification for Saudi missile defense efforts.

Lockheed Martin was awarded a $1.48 billion contract modification to build the Terminal High Altitude Area Defense (THAAD) missile defense system for Saudi Arabia, bringing the total value of the deal to $5.36 billion, the U.S. Department of Defense said on Friday.

“Lockheed Martin Corp., Missiles and Fire Control, Dallas, Texas, is being awarded a firm-fixed-price, $1,473,941,756 modification (P00019) to previously-awarded contract HQ0147-17-C-0032 for the procurement of Terminal High Altitude Area Defense (THAAD) Interceptor support items in support of the Foreign Military Sales (FMS) case to the Kingdom of Saudi Arabia (KSA),” said Department of Defense.

Also added that the period of performance is from July 19, 2019, through July 31, 2023.

According to UPI.com, THAAD provides the missile defense system with a globally transportable, rapidly deployable capability to intercept and destroy ballistic missiles inside or outside the atmosphere during their final, or terminal, phase of flight.

The Defense Security Cooperation Agency reported in 2017 that the Government of Saudi Arabia has requested a possible sale of 44 THAAD launchers, three hundred sixty THAAD Interceptor Missiles, sixteen THAAD Fire Control and Communications Mobile Tactical Station Group and seven AN/TPY-2 THAAD radars. The estimated cost is $15 billion.

“This potential sale will substantially increase Saudi Arabia’s capability to defend itself against the growing ballistic missile threat in the region,” said in DSCA’s statement.

THAAD’s exo-atmospheric, hit-to-kill capability will add an upper-tier to Saudi Arabia’s layered missile defense architecture and will support modernization of the Royal Saudi Air Defense Force (RSADF).