Japan is likely to choose the US-made F-35 jet as its next frontline fighter, to replace its current model, the F-4.

Japanese media says the ministry of defence will announce its decision on Friday. It suggests Japan will initially purchase 4 F-35s by 2012 with a plan to acquire 40 more in the future.

However, the reports also doubt the new fighters will be deployed quickly due to the rising costs and slow development process.