Japan tests interceptor missile

The Japanese military has successfully test-fired an interceptor missile from a ship at sea, destroying a mid-range ballistic missile in space.

Monday's $55m test off Hawaii was the first time a US ally had shot down a ballistic missile from a ship at sea.

The Japanese navy and the US missile defence agency called the test "a major milestone in the growing co-operation between Japan and the US".

But it may deepen Chinese concerns that Tokyo could use the technology to help the US defend Taiwan if conflict erupted across the straits.

The interceptor fired by the JS Kongo knocked out the target warhead about 160km above the Pacific Ocean, said the US agency, which carried out the test together with the Japanese and US navies.

The JS Kongo is the first of four Japanese destroyers due to be outfitted to counter missiles that could carry chemical, biological or nuclear warheads.

North Korean threatExperts say the test target resembled the Rodong missile owned by North Korea, which has a shorter range than the Taepodong missile North Korea sent over Japan nearly a decade ago.

But North Korea is believed to have an arsenal of about 200 Rodongs, and Japanese defence experts say it represents the greatest threat to Japanese security.

Riki Ellison, a prominent missile-defence advocate who monitored the test, said that by intercepting a missile similar in speed and size to those in North Korea's arsenal "Japan has proven its capability to defend and protect their country from North Korean missiles".

Tokyo has invested heavily in missile defence since North Korea test-fired a long-range missile over northern Japan in 1998.

Shigeru Ishiba, Japan's defence minister, described the successful test as "extremely significant".

"We will continue to strive to increase the system's credibility," he said, insisting the missile shield was worth the high cost.

"We can't talk about how much money should be spent when human lives are at stake."

Japan plans to have spent a total of $11.2bn on missile defence over the four years to March 2008 using the US-developed Aegis combat system, according to the defence ministry.

China offered a muted reaction to Japan's anti-missile test, saying only that it hoped Tokyo's actions would be positive for peace and trust in Asia.

"We hope that the actions of Japan are beneficial to the peac and stability of the region and conducive to mutual trust of the countries in the region," Qin Gang, China's foreign ministry spokesman, said.