Japan is to refocus its defence strategy to counter the rise of China, new guidelines revealed.
It will boost its armed forces after the cabinet approved new policies which also call for a stronger alliance with the US - Japan's biggest ally - and expanded security networks with partners like South Korea and Australia.
Traditionally Japan has concentrated on the Cold War threat of Russia.
Japan will acquire new submarines and fighter jets, upgrade its missile defence capabilities and make its ground forces more mobile so that they can quickly respond to emergencies in southwest Japan.
While Japan has forces for self-defence, its pacifist constitution, drafted by the US after the Second World War, bar it from sending troops into combat overseas.
The guidelines paint China as a bigger threat than Russia and say Japan is shifting its defence emphasis from the northern island of Hokkaido to islands in the south, such as Okinawa and territories claimed by both Tokyo and Beijing that have recently led to diplomatic tensions.
China immediately criticised the guidelines as "irresponsible."
The Japan-US alliance remains "indispensable" to Japan's security, the statement said, calling for stronger co-operation between Japanese and the 47,000 US armed forces based in this country.
But it also noted a relative decline of America's strength and rise of emerging countries such as China and India. Japan, meanwhile, should pursue its own efforts to enhance missile defence capabilities to protect itself from threats by China and North Korea, it said.
The new strategy document also said North Korea's military activity is a "pressing and serious destabilising factor" for Japan.