The F-35 partners' meeting in Sydney was the second in two weeks, following one in Washington, as some nations review their orders for the F-35 Joint Strike Fighter.
"We have been given the adequate time needed to execute the program," Air Force Major General John F. Thompson, deputy Joint Strike Force Program Executive Officer, told reporters.
"There was plenty of lively discussion on affordability and production. What we pledged today was to maintain a very open line of communication."
The US Defense Department is restructuring for a third time its $382 billion F-35 programme with Lockheed Martin Corp to allow more time for development and testing.
Continued schedule delays and talk of lingering technical issues have prompted some countries to rethink their orders. The group includes Britain, Australia, Turkey, Canada, Denmark, Norway, Italy and the Netherlands.
The Canadian government, which has been a staunch defender of the costly F-35 program, said on Tuesday it had not ruled out the idea of withdrawing. Canada plans to buy 65 warplanes.
Japan, which has ordered 42 F-35s, has also warned Washington it may cancel orders due to rising costs.
The Pentagon last month said it was putting off its own orders for 179 F-35s over the next five years to save $15.1 billion, as President Barack Obama seeks $487 billion in defence budget cuts over the next decade.
Lockheed Martin said the postponement would increase the price of the warplane. U.S. officials insist they have not changed their plans to develop and buy a total of 2,443 jets.
The long-awaited first flight of an F-35 last week at Eglin Air Force Base in Florida was cut short by a possible fuel leak.
"I am absolutely confident that we will get where we want to go," said Thompson. "But from a procurement standpoint, it's up to each partner to decide what they want to procure and how much they want to procure to address their capability gaps."
Britain, the biggest outside contributor to F-35 development, has said it would wait until 2015 to decide how many jets to buy. Australia will decide in 2012 whether to continue with the purchase of 100 F-35 jets.
The United States expects to sell more than 700 F-35s to international partners over the next decade.