Japan has for the first time shot down a ballistic missile, testing a defence system aimed at warding off potential missile threats from its neighbours.
A Japanese warship stationed off Hawaii launched a US-developed Standard-3 interceptor missile to destroy a mock target fired from onshore.
The test was carried out in partnership with the US Missile Defense Agency.
Experts say the test will strengthen the US-Japan security alliance but it could also escalate regional tensions.
Japan and the US have worked closely on missile defence since North Korea flew a missile over northern Japan in 1998.
The US has carried out such tests in the past but this is the first time a test has been carried out by one of of its allies.
Japanese government spokesman Nobutaka Machimura described the test as very significant for Japan's national security.
"The Defence Ministry and the government have been putting efforts into the development of ballistic missile defence, and we will continue to install the needed equipment and conduct exercises," he said.
The BBC's correspondent in Japan, Chris Hogg, said the test could cause unease among Japan's neighbours.
China in particular is likely to be concerned that if it ever decides to attack Taiwan the system could be used to help the US defend the island, he said.
So far, the Chinese response has been muted, with the Beijing authorities referring indirectly to the test in a regular press briefing.
"We have taken note that Japan has reiterated many times it will follow the path of peaceful development," said spokesman Qin Gang.
"We hope that the actions of Japan are beneficial to the peace and stability of the region and conducive to mutual trust of the countries in the region."
North Korea threat
The target, which a US official said resembled "a North Korean scud-like missile," was fired from the US Navy's Pacific Missile Range Facility on the Hawaiian island of Kauai.
JAPAN'S MISSILE DEFENCE SYSTEM
The Standard Missile-3 (SM-3) launches from the sea to intercept missiles in space
It is complemented by Patriot Advanced Capability-3 (PAC-3) which intercepts missiles as they descend
The programme is estimated to have cost 127bn yen ($1.2bn; £560m) over four years
It uses the US-developed Aegis combat system
A Japanese vessel, the JS Kongo, tracked the missile and then fired its interceptor after three minutes, destroying the target some 160km (100 miles) above the Pacific Ocean.
Japan ultimately plans to install missile interceptor systems on four of its destroyers equipped with the high-tech Aegis tracking system.
Japan and the US accelerated co-operation on missile defence after Pyongyang test-fired a long-range Taepodong-1 missile over northern Japan and into the Pacific in 1998.
North Korea is also thought to have an arsenal of medium-range Rodong missiles capable of striking Japan. The test target was said to resemble one of these.
This test marks a second stage of Japan's expanding missile defence.
Land-based Patriot Advanced Capability 3 (PAC-3) missile defence systems have already been installed at two bases in Japan, with further installations planned.
Defence Minister Shigeru Ishiba dismissed concerns about the high costs of the programme, estimated to be several billion dollars, and said Japan would continue working to increase the credibility of the system.
"We can't talk about how much money should be spent when human lives are at stake," he told reporters.