Prime Minister Tony Abbott has confirmed Australia will acquire two additional Boeing C-17 airlifters.

The Royal Australian Air Force’s 36 Squadron already operates a fleet of six C-17 Globemasters from its Amberley base, with the seventh to be delivered in July/August and the eighth aircraft to be delivered by the end of this year, the Prime Minister announced at Amberley on Friday.

The $1 billion acquisiton comprises $700 million for the two aircraft plus sustainment, and a further $300 million for a new, dedicated C-17 maintenance hangar and aircraft hardstand and taxiway upgrades at Amberley. Currently 36SQN utilises the KC-30 maintenance hangar at Amberley when needed.

“The two additional C-17s will provide vital heavy airlift support to a range of regional and global coalition operations and greatly increase Australia’s ­capacity to provide rapid and effective disaster rescue and relief and humanitarian aid,” Prime Minister Abbott said.

The acquisition of the two extra C-17s was first announced by then Defence Minister Senator David Johnston last October. At the time Johnston said Australia would also consider the acquisition of an ninth and tenth C-17, with decisions regarding those aircraft to be informed by the Force Structure Review being developed as part of the 2015 Defence White Paper process.

Then on November 12 a US Defense Security Cooperation Agency notification revealed Australia had formally requested “up to four” more C-17s from the US government

With production of the C-17 ending this year, Boeing has built about 10 “white tail” aircraft in anticipation that these could be sold to new or existing customers of the airlifter. New Zealand has shown interest in two while there is believed to be interest for additional aircraft from India, Canada and the UK, as well as new customers in the Middle East.

Australia initially ordered four C-17s in 2006 which were delivered between December that year and January 2008. The fifth and sixth aircraft were delivered in 2011 and 2012.

“Boeing is honoured by Australia’s decision to acquire two additional C-17A Globemaster III aircraft, which further highlights the enduring relationship between Boeing and the Commonwealth,” Boeing said in a statement welcoming the announcement of the additional aircraft.

“Since 2006, the Royal Australian Air Force has operated its six C-17s on the frontlines of military operations and humanitarian missions. As Australia and customers around the world have experienced first-hand, the C-17 remains unmatched in its ability to transport troops and heavy cargo, support airdrops and aeromedical evacuations, and land and takeoff in remote airfields.”