Japan is to buy F-35 stealth fighter jets from the United States to replace F-4s as the mainstay of its air defence fleet.
Tokyo announced it would buy a total of 42 of the Joint Strike Fighters from Lockheed Martin, in a deal worth some $US8 billion.
The jet was chosen over the Eurofighter Typhoon and Boeing F/A-18 Super Hornet.
The BBC reports the announcement came amid regional uncertainty following the death of North Korean leader Kim Jong-il.
There is also growing concern in Japan about China's increasing military might. In recent months, Japan has said it is bolstering its coastal defences.
The BBC reports the decision was widely expected. Analysts say it is likely to trigger more orders, including from South Korea.
Exact details of the contract, including numbers and timings, are yet to be determined.
