The governing party in Japan has agreed plans to deploy a highly-expensive satellite spy system, after failing to detect a rocket launch by North Korea in August which exposed Japan's vulnerability to such attacks.

The proposal by the Liberal Democratic party to spend one-point-seven-billion dollars on multiple intelligence satellites is expected to be discussed by the government next week.

The BBC Tokyo correspondent says Japan had to rely on American intelligence after failing to detect the North Korean rocket which passed over its territory.

But she says officials are keen to reassure Japan's neighbours -- China and South Korea -- that the spy satellites do not mark a return to militarism.