Japanese Defence Force soldiers load Patriot missiles onto a ship setting sail to the southern Okinawa islands ahead of a North Korean rocket launch.
The isolated and impoverished country announced on Saturday that it planned to launch a rocket some time in the next three weeks, despite a U.N. ban on such activities.
North Korea says the rocket is boosting a satellite into orbit, but Washington and Seoul believe it is testing intercontinental ballistic missiles capable of carrying nuclear warheads.
Japan believes the rocket will pass over Japanese territory above the Okinawa islands and is preparing to intercept it, should the missile stray off its path.
In an effort to ease tensions, South Korea hosted a meeting on Monday with representatives from the U.S., Japan, China and Russia.
Earlier South Korea's unification ministry called on North Korean officials to halt the rocket launch.
China, a long-time ally of North Korea, echoed the South's statement and asked regional neighbours to prevent the situation from worsening.
North Korea failed to launch a similar rocket in April on the 100th anniversary of the birth of the country's founder.
Japan prepares for North Korean rocket (1:14)
Dec. 3 - Japan sends Patriot missiles to Okinawa in order to intercept possible North Korean rocket launch as regional leaders call for calm. Jessica Gray reports. ( Transcript )