WASHINGTON — The U.S. State Department has approved a potential sale of two different helicopters to the Philippines, in advance of that country’s final decision on what system to buy.

The Philippines was cleared to buy six AH-1Z Viper attack helicopters and related equipment, produced by Bell, with an estimated price tag of $450 million.

A much more expensive option, for six Boeing-made AH-64E Apache attack helicopters and related equipment, comes with an estimated cost $1.5 billion.

“The Philippines is considering either the AH-1Z or the AH-64E to modernize its attack helicopter capabilities,” according to a notification posted to the website of the Defense Security Cooperation Agency. “The proposed sale will assist the Philippines in developing and maintaining strong self-defense, counterterrorism, and critical infrastructure protection capabilities.”

DSCA notifications are not final sales; once cleared by Congress, the sales enter negotiations, during which quantities and costs can shift. In this case, the choice of either American-made platforms is not guaranteed; Manilla is also considering the Turkish-made T129 ATAK. However, the U.S. State Department often preapproves potential sales of systems to foreign countries so that if the foreign partner does select an American-made weapon, the process will move more quickly.

Should the Philippines select the AH-1Z package, it would come with 14 General Electric T700-401C engines, seven Honeywell Embedded Global Positioning Systems/Inertial Navigation with Precise Positioning Service, six AGM-114 Hellfire II missiles, and 26 Advanced Precision Kill Weapon System all-up rounds, among other equipment.

The AH-64E package would come with 18 General Electric T700-701D engines, 15 Honeywell Embedded Global Positioning Systems/Inertial Navigation with Precise Positioning Service, 200 AGM-114 Hellfire missiles, 300 Advanced Precision Kill Weapon System kits, and 200 FIM-92H Stinger missiles, among other gear, equipment, U.S. government and contractor technical assistance, technical and logistics support services, and other related elements of logistics support.

In either case, industrial offsets are expected to be part of the winning package; such offsets are negotiated directly between the customer nation and the industry partner.