TOKYO - Japan took the rare step Friday of ordering missile-equipped battleships and missile interceptors to protect the northern coast, preparing should a rocket launch by communist North Korea go awry. Still, Tokyo urged calm and said the likelihood of rocket debris falling on the country was low.

North Korea plans to launch its Kwangmyongsong-2 satellite April 4-8, designating a zone near Japan's northern coast where debris is likely to fall.

Japan, South Korea and the U.S. suspect North Korea will use the launch to test the delivery technology for a long-range missile capable of striking Alaska. Amid heightened regional tensions, the communist nation has warned that any attack on its satellite could be an act of war.

Tokyo has repeatedly urged Pyongyang to refrain from the launch. But Defense Minister Yasukazu Hamada on Friday ordered the deployment of missile interceptors to the area at risk, vowing to "eliminate anything that may cause us any damage."

Under the order, Japan's military will deploy two missile-equipped destroyers to the Sea of Japan and send batteries of Patriot missile interceptors to protect the northern coast.

Prime Minister Taro Aso, who chaired Japan's National Security Council earlier in the day, said the military deployment was to ensure security, but added the possibility of debris falling on Japanese territory is very low. The security council approved Hamada's order to mobilize the missile interceptors.

"By any chance, if any flying objects fall on our territory, we have to respond to ensure safety for our citizens," Aso said Friday, according to Kyodo News agency. But the premier said such a possibility was remote. Chief Cabinet spokesman Takeo Kawamura urged people "to remain calm" and repeated that falling debris was "unlikely."

Tokyo's deployment comes as Japan's nuclear envoy will meet his U.S. and South Korean counterparts in Washington to coordinate a joint strategy.

U.S. intelligence officials say North Korea mounted a rocket on a launch pad on its northeast coast, putting Pyongyang well on track for the launch. Citing an unnamed diplomatic official, South Korea's Chosun Ilbo newspaper also said North Korea is now "technically" capable of a launch in three to four days.

Along with Japan, South Korea and the U.S. prepared deployments of their own.

Seoul is dispatching an Aegis-equipped Sejong the Great destroyer off the east coast to monitor the launch, a military official in Seoul said. He asked not to be named because he was not authorized to speak to the media.

Two U.S. Aegis-equipped ships, docked at a South Korea port, will also set sail in coming days, U.S. military spokesman Kim Yong-kyu said.

The U.S. and South Korea warned Thursday it would be a major provocation with serious consequences, and Japan's parliament was expected to issue a resolution next week demanding the launch be scrapped.

Regional powers have said any launch is banned under a 2006 U.N. Security Council resolution and would trigger sanctions.

Secretary of State Hillary Rodham Clinton warned that such a "provocative act" could jeopardize the stalled talks on supplying North Korea with aid and other concessions in exchange for dismantling its nuclear program.

Of all the North's neighbors, Japan has reacted the most strongly because the satellite will fly over its airspace. North Korea sent a similar rocket over Japan in 1998, prompting Tokyo to build up its missile defenses.

Under Friday's order, the Japanese military is allowed to shoot down any missile fragments and debris heading toward Japanese territory.

The military will move some PAC-3 land-to-air missiles, currently deployed around Tokyo, to Japan's northern coast, and deploy a pair of destroyers carrying SM-3 sea-to-air missiles in nearby waters, the Defense Ministry said in a statement.

A set of the PAC-3 missiles would be also brought into central Tokyo to defend the nation's capital. The destroyers, equipped with Aegis radar, will sail from their southern homeport of Sasebo.

Japan and others are also threatening sanctions.

Japan imposed tight trade sanctions on Pyongyang in 2006 after it tested ballistic missiles in waters dividing the two countries and conducted an atomic test. Japan's current sanctions, which have been extended every six months, are set to expire April 13.