The Japanese destroyer Kirishima on Saturday left the Yokosuka base in Kanagawa Prefecture for the East China Sea ahead of a planned rocket launch by North Korea, Kyodo News reported.
The Kirishima, equipped with sea-based interceptor missiles, will deploy with two other warships to shoot down the rocket in space if it begins falling on Japanese territory.
Ground-based Patriot Advanced Capability-3 interceptors will also be deployed on Miyako Island, Okinawa Prefecture, the agency said.
Pyongyang says the rocket will put an earth observation satellite into orbit.
The U.S. has said the launch would violate a UN Security Council resolution and constitute a missile test. Japan and South Korea have also condemned the launch.
North Korean officials insisted the launch is part of a peaceful space program and said the Kwangmyongsong-3 satellite will circle along the solar synchronous orbit at an altitude of 500 kilometers for two years.
The launch, scheduled to take place between April 12 and 16, is intended to mark the 100th birthday of the nation's late founding leader Kim Il-sung.