''We are concerned about it firstly from the point of view of peaceful use of space and secondly from the safety perspective,'' Chief Cabinet Secretary Yasuhisa Shiozaki told a news conference today.
Using a ground-based medium-range ballistic missile, the test knocked out an aging Chinese weather satellite about 865 km above the earth on January 11 though ''kinetic impact,'' or by slamming into it, the National Security Council said earlier.
Japan has asked the Chinese government for confirmation that the test took place and for an explanation of what China's intentions were, Shiozaki said.
Pacifist Japan, which has been patching up relations with China damaged by disputes over wartime history, has long been concerned about its giant neighbour's rising military strength and has called for more transparency from China on defence spending.
Last March, China announced a 14.7 rise in defence spending to 35.3 billion dollar.
The United States, Australia and Canada have already conveyed their concerns over the missile test to Beijing.
The last US anti-satellite test took place on September 13, 1985. Washington then halted such Cold War-era testing, concerned by debris that could harm civilian and military satellite operations.
REUTERS SSC HS1008