A request from Saudi Arabia to procure MK 15 Phalanx Close-in Weapons System upgrade kits from the United States has been approved by the State Department.

The five kits -- plus additional equipment, training and logistics support -- would be obtained through the U.S. Foreign Military Sales program at a cost of $154.9 million.

"The proposed sale will provide Saudi Arabia with self-defense capabilities for surface combatants supporting both national and multi-national naval operations," said the U.S. Defense Security Cooperation Agency in a notification to Congress. "Saudi Arabia will use the enhanced capability as a deterrent to regional threats and to strengthen its homeland defense."

DSCA manages the FMS program Saudi Arabia and is required to report possible sales to Congress.

Phalanx is a radar-guided 20mm Gatling gun for close-in defense against anti-ship missiles and vessels. Its effective range is 2.2 miles. The gun's rate of fire is 4,500 rounds a minute.

The system performs search, detection, threat evaluation and tracking. The Block 1B version adds forward-looking infrared sensors, and a control station that allow operators to visually track and identify targets.

Raytheon, maker of the Phalanx, said the upgrade allows Phalanx to be used against helicopters and high-speed surface craft.

The prime contractor for the proposed FMS sale would be Raytheon Missiles Systems.