Australia is reviewing its timetable for buying 12 troubled F-35 Joint Strike Fighters, the defence minister said Monday after the United States announced a rethink of its purchase schedule for the futuristic warplanes.

Australia is a funding partner in developing the JSF, which the U.S. Defence Department describes as the largest fighter aircraft program in history. The Lockheed Martin Corp. JSF program has been troubled by repeated blowouts in cost as well as delivery schedules.

Most of the funding for the fighter comes from the United States, while Canada, Turkey, Britain, Italy, Norway, Denmark and the Netherlands are also funding partners.

Australian Defence Minister Stephen Smith said Monday that Canberra is only contractually obligated to take delivery of two of the warplanes. They will be based in the United States and be available from 2014 for training Australian pilots.

Smith said Australia is reconsidering its schedule of buying another 12 during the following three years.

"We will now give consideration to whether the timetable for the purchase of those 12 Joint Strike Fighters should occur on the same timetable," Smith told reporters.

Smith is concerned that any decision by the U.S. to reduce the number of jets it produces for its own forces would create another cost blowout. Last week, U.S. Defence Secretary Leon Panetta announced major reductions in the U.S. defence budget, and while the JSF program remained intact, he said "procurement would be slowed."

Smith said in August last year that he would announce in 2012 whether Australia will invest in an alternative fighter such as the Boeing Co. Super Hornet to ensure that schedule delays do not compromise Australia's air force capabilities.

Costs rising

Lockheed Martin, in conjunction with Northrop Grumman and BAE Systems, is building 2,400 of the next-generation fighter jets for the U.S. as well as the partner nations. But the cost of the program has jumped to $385 billion US from $233 billion. Some estimates suggest that it could top out at $1 trillion over 50 years.

Australia had planned to buy as many as 100 of the fighters for $17 billion. But the government will announce this year whether any more than 14 will be bought for about $3.5 billion.

Australia has 71 standard F/A-18 Hornets that are due to retire around 2020.

Australia last year took delivery of the last four of 24 F/A-18F Super Hornets. The Super Hornets, built by Boeing in conjunction with Northrup Grumman, GE Aircraft Engines and Raytheon, were ordered in 2007 to maintain Australia's air force capabilities during the transition to the JSF over the next decade.