TOKYO (AFP) - Japan said Tuesday it was technically unable to shoot down a missile fired over its territory at the United States, even as it moves to be legally able to do so.
Tokyo and Washington have been improving their defences to protect the officially pacifist country from North Korea, which lobbed a missile over Japan's main island in 1998.
"The missile system that our country is now introducing is aimed consistently at defending our country," Prime Minister Shinzo Abe said in a written reply to questions from an opposition lawmaker.
"But since missiles heading to other countries are supposed to fly fairly high, technically it is extremely difficult to intercept such missiles," the statement said.
Japan relies on US protection under a security alliance reached after World War II, when Washington forced Tokyo to renounce war.
Since taking office last year, Abe has tried to shed legacies of defeat, moving to revise the US-imposed pacifist constitution and to build a more reciprocal relationship with Washington.
Abe has appointed a panel to find the legal grounds to allow Japan to shoot down a missile aimed at the US without violating the existing constitution.
Successive governments have interpreted the constitution as permitting Japan to use force to defend itself but not its allies.
Japan's annual defence report warned last week that North Korea is improving its missile system to cover all east Asia, including Japan, and potentially reach the northern tip of Australia as well as parts of Alaska.