Australia also has 24 of the new generation F/A-18F Super Hornets, which entered service in 2010 and 2011, and 12 of those have been upgraded with sophisticated U.S. jamming equipment.

Smith said Australia would write a letter of request to the United Sates, seeking cost and availability information for an extra 24 Super Hornet under the U.S. Foreign Military Sales programme. But he said no decision had been made to buy more Super Hornets.

Australia is one of the eight international partners helping fund the development of the F-35, although delays and increased costs, as well as budget pressures, have prompted some countries to wind back or delay their orders.

The United States has also delayed orders, while the Netherlands and Italy have both cut back on their orders. The other partner countries are Britain, Norway and Turkey.