America expects the per-plane cost of the controversial F-35 Joint Strike Fighter to fall to $US80 million ($A104 million) by 2020, which could mean significant flow on savings for Australia.
US F-35 program head Lieutenant General Chris Bogdan made the price prediction during a briefing at the Avalon Airshow in Melbourne on Tuesday.
The current batch is costing $US94.6 million ($A123.1 million) per plane.
"I see that number continuing to come down for a very long time," Lieutenant General Bogdan said.
"I think we can get there (to $US80 million per plane by 2020)."
Australia plans to buy 72 jets, from Lockheed Martin, to replace the ageing FA-18A/B Classic Hornets, with the first expected to enter service from late 2018.
The government has allocated $17 billion to the purchase.
Defence Industry Minister Christopher Pyne said last month the recent per plane price drop to below $US100 million ($A130 million) represented a 25 per cent reduction from the price of the fighter in 2014 for Australia.
Lieutenant General Bogdan said the program was in the middle of the biggest ramp up in production ever, and even though there was some risk to the supply chain, everything was on track.
Australian Air Vice-Marshal Leigh Gordon said there had not been delays or increased costs to Australia's program so far.
Australia's first two jets are making their debut at the airshow later this week.
The jets have been based in Arizona in the US, where four Australian pilots are learning to fly them.
A fifth pilot is due to depart for the US in coming months for training.
After the airshow the jets will return to the US.