North Korea says it’s now in the process of injecting fuel into a long-range rocket ahead of a planned launch that’s been condemned internationally.
Pyongyang says the launch, due over the next few days, is simply designed to put a weather satellite into space.
But several western countries believe the real aim is to test a missile that could carry a nuclear warhead.
The launch has caused alarm among North Korea’s neighbours. The Philippines is re-routing air traffic. Japan says it will shoot down the rocket if it crosses its airspace.
The government’s chief spokesman in Tokyo Osamu Fujimura said the route that had been announced was mostly over the ocean, but precautions were still being taken. He called on the public to continue going about their daily lives calmly.
He said the government was beefing up its preparations, setting up a crisis management office for the missile launch.
Japan has been getting its missile defence systems ready since last month. Patriot missiles have been deployed in central Tokyo since the weekend.
Other ground-based interceptors have been set up in the south of the country.
The Japanese fear a repeat of an earlier North Korean rocket launch in 2009 that flew over their airspace.