CANBERRA, Australia (AP) -- Australia announced Wednesday that it had increased its order for F-35 Joint Strike Fighters by 58, to 72, to be fully operational by 2023 in a declaration of confidence in the troubled stealth war plane.
The government expects the additional 58 U.S. jets, developed by Lockheed Martin Aeronautics Co., to cost 12.4 billion Australian dollars ($11.5 billion), Prime Minister Tony Abbott said.
"This is one of the largest defense purchases that Australia has ever made," Abbott told reporters. "It will ensure our edge as a regional power."
The F-35 is the Pentagon's most expensive weapons program and has been troubled by schedule delays and cost overruns.
Abbott said he was confident that the cost per jet would continue to fall with time.
"We are confident that all of the logistical issues are well on the way to being ironed out," he said.
Australia had written into the contract flexibility to defer orders if there is an excessive cost blowout, Defense Minister David Johnston said.
Australia, a funding partner in developing the F-35, ordered its first 14 jets in 2009. Most of the funding comes from the United States, while Canada, Turkey, Britain, Italy, Norway, Denmark and the Netherlands are also funding partners.