The Turnbull government is set to spend $7 billion on several long-range, surveillance drones in the hope of increasing ability to spot ships in the seas of Asia and strengthen relations with the US.

The drone program comes as part of an alliance between Australia and the US which will see the two nations operating on shared missions as needed.

The first aircraft will come into service in 2023 and will have the capability to monitor an area the size of Switzerland in one day.