The U.S. State Department has approved the potential sale of 29 Boeing Co (BA.N) AH-64E Apache attack helicopters to Australia in a deal valued at up to $3.5 billion, the Pentagon said on Thursday. The sale is one of a string of Australian purchases in April that included 12 MQ-9B drones and related equipment for about $1.6 billion, $1.6 billion in tanks and heavy armored combat vehicles and four CH-47F cargo helicopters for as much as $259 million. Thursday"s package would include the choppers, 69 spare engines and night vision equipment, as well as munitions such as 85 AGM-114R Hellfire missiles, support equipment, spares and technical support, the Pentagon said. The Pentagon"s Defense Security Cooperation Agency notified Congress of the possible sale on Thursday. The State Department said, "The proposed sale will improve Australia’s capability to meet current and future threats." Previously the State Department has called Australia "one of our most important allies in the Western Pacific." Despite approval by the State Department, the notification does not indicate that a contract has been signed or that negotiations have concluded. The Pentagon said Boeing was the prime contractor for the weapons.