Japan on Thursday dispatched three destroyers to waters over which Pyongyang says its rocket will travel.
Television footage showed three Aegis destroyers armed with SM-3 missile interceptors leaving their base in Sasebo, some 900 kilometres (560 miles) west of Tokyo.
They were reportedly bound for the East China Sea and the Sea of Japan, a stretch of water known to Koreans as the East Sea.
Separately, a naval ship carrying PAC-3 (Patriot Advanced Capability-3) ballistic missiles arrived in the Okinawan island of Miyakojima on Thursday morning.
Television footage showed Self-Defence Force units unloading the missiles from the vessel at a harbour on the island, which lies on the expected flight path of the rocket.
In Tokyo, the defence ministry has deployed another PAC-3 battery at its headquarters as part of its effort to intercept anything headed towards the Japanese mainland.
Prime Minister Yoshihiko Noda's cabinet plans to hold a security meeting on Friday to issue an advance order to shoot down the rocket if it looks set to fall on Japanese territory, Jiji Press reported.
Japan deploys missile defense around Tokyo ahead of DPRK rocket launch
Japan will deploy its Patriot anti- missile defense system in both Okinawa and around Tokyo to guard against this month’s planned rocket launch by the Democratic People’s Republic of Korea, the Japanese Defense Ministry said in a statement Wednesday.
The defense ministry said the rocket is expected to fly over islands in southwestern Japan, but there is also a need to protect the capital city of Tokyo. The Patriot missle defense was reportedly deployed at the Ground Self-Defense Forces’ training fields in Narashino and Saitama around the capital.
Ships carrying PAC-3 missile interceptors set out for Okinawa from a naval base in Hiroshima, Defense Ministry spokesman Takaaki Ohno said. The move follows an order issued by Defense Minister Satoshi Morimoto over the weekend.
Pyongyang said last weekend it will fire a rocket between Dec. 10 and Dec. 22 to put a satellite into space.
Japanese Prime Minister Yoshihiko Noda urged DPRK to “exercise self-restraint” and called for close cooperation with the U.S., South Korea, China and Russia to push Kim Jong Un to abandon the plan.