U.S. allies are asking the United States for modernization of airborne warning and control aircraft and procurement of air-to-air missiles.

The separate requests -- from Saudi Arabia and Turkey -- were reported to Congress earlier this month have already been approved by the State Department.

The U.S. Defense Security Cooperation Agency, which brokers FMS deals, said their combined total is worth more than $2.3 billion and would contribute to U.S. foreign policy objectives.

The Kingdom of Saudi Arabia is specifically seeking five AWACS Block 40/45 mission computing upgrade systems, 20 next-generation Identification Friend or Foe AN/UPX-40 systems, communication equipment, provisioning, and spare and repair parts for their aircraft.

The Block 40/45 major defense equipment includes new mission computing hardware and software with open architecture – including computers, servers, and mission interactive displays.

Support equipment personnel training and training equipment would also be part of the package, which continues efforts to maintain interoperability with U.S. and coalition forces, DSCA said.

The estimated cost: $2 billion. The principal contractor: Boeing.

"The Royal Saudi Air Force's AWACS fleet provides early warning of potential airborne threats to Saudi Arabia and manages friendly airborne assets," the agency said. "The sale of this equipment and support will enhance the RSAF's ability to effectively field, support, and employ this aircraft for the foreseeable future."

Turkey, meanwhile, is seeking the purchase of 145 AIM-120C-7 Advanced Medium Range Air-to-Air Missiles for use by its air force's F-16 fighters and, eventually, F-35 aircraft to maintain its air-to-air capability to defend its extensive coastline and borders against future threats.

The deal, worth about $320 million, includes associated equipment, including missile guidance sections, launchers, containers, support equipment, spare and repair parts and integration activities.

"Turkey is a partner of the United States in ensuring peace and stability in the region," the agency said. "It is vital to the U.S. national interest to assist our NATO ally in developing and maintaining a strong and ready self-defense. This proposed sale is consistent with those objectives."

The principal contractor would be Raytheon. If the sale is approved, U.S. government and contractor personnel would be required to make multiple trips to Turkey for technical reviews and support, program management, training, integration and testing.

U.S. Foreign Military Sales deals are seen as promoting military-to-military relationships with allied nations by facilitating the purchase of equipment and services and as a way of advancing interoperability. Before fiscal 2006, the value of FMS deals was $10 billion - $13 billion annually, the agency said, but is now expected average about $30 billion annually.

"The idea is, if partners have U.S. equipment and U.S. training and are following U.S. doctrine, out interoperability is greater with them," Derek Gilman, DSCA's general counsel said last year. "That can lead, if you are sharing joint doctrine, to joint exercises and other types of military-military cooperation and ... to decades-long relationship, core relationships, with partners around the world."

In other FMS-related news, Canada has asked the United States for $225 million worth of AN/AAQ-24(V) Large Aircraft Infrared Countermeasures (LAIRCM) systems and associated equipment, parts, training and logistical support.

The systems would be used on its CP-140 long range patrol planes.