Australia is looking to spend about $183.7 million on anti-radiation missiles for its Growler aircraft fleet, according to a US defence agency.
The US State Department has approved the possible sale and Congress has been notified, a news release from the country's Defense Security Cooperation Agency says.
The sale would include up to 70 high speed anti-radiation missiles, 40 advanced anti-radiation guided missiles and training missiles as well as other support equipment.
The total estimated cost is $US137.6 million, or $183.7 million.
"Australia is requesting these missiles for its Electronic Attack EA-18G Growler aircraft," it says about the missiles, which are designed for attacking ground-based radar.
"Australia will use this capability as a deterrent to regional threats and to strengthen its homeland defense."
The notice is only of potential sale, not that the sale has concluded.
If it goes ahead, the "sale will contribute to the foreign policy and national security" of the US, by "helping to improve the security of a major contributor to political stability, security, and economic development in the Western Pacific".
"Australia is an important major non-NATO ally and partner that contributes significantly to peacekeeping and humanitarian operations around the world," the notice reads.
"It is vital to the US national interest to assist our ally in developing and maintaining a strong and ready self-defense capability."