North Korea has test fired at least two missiles, which landed in the Sea of Japan about 500km off the western coast of Japan's main northern island of Hokkaido.
There are reports that a third missile was also launched, but it failed in-flight.
It has not been confirmed whether the long-range Taepodong-2 missile was launched.
Last week. Japanese Prime Minister Junichiro Koizumi said that he and US President George W Bush had agreed to impose unspecified 'pressures' on North Korea if it launched such a long-range missile.
Japan is particularly sensitive to such moves by North Korea, which in 1998 fired a Taepodong-1 missile over Japan into the Pacific, prompting Tokyo and Washington to step up co-operation on missile defence.
Preparations for the launch of a multi-stage Taepodong-2, with a range of up to 6,700km, have been underway for several weeks on the remote northeast coast of North Korea.
