Japanese officials said they are taking all necessary precautions to protect their citizens in anticipation North Korea will conduct a provocative missile launch as early as Saturday.
The two countries, which have no diplomatic relations, have traded retaliatory warnings this week.
Japan has deployed land-to-air missile interceptors in case any debris threatens to fall on this country.
North Korea, which says it will conduct a peaceful launch of a communications satellite, has threatened to respond with what it called "deadly blows" against Japanese cities if Tokyo tries to shoot down its satellite.
Japan's defense minister, Yasukazu Hamada, said whether Pyongyang actually launches a satellite or a ballistic missile the country's military force is prepared to protect the nation.
Hamada said necessary preparations have been completed and appropriate units are deployed.
Patriot PAC-3 guided missiles are in place in Iwate and Akita prefectures, below the path Pyongyang has announced its rocket will traverse. Similar interceptors are protecting the capital, Tokyo.
Japan, along with the United States and South Korea, have stated that North Korea appears set to carry out a long-range ballistic missile test that would violate a United Nations Security Council resolution approved in 2006 barring Pyongyang from such a launch. The Security Council resolution was put in place after North Korea' first nuclear weapons test and the launch of a ballistic missile.
U.S. President Barack Obama told reporters in France Friday that the North Korean launch is provocative and should be stopped. He said the United States will "take appropriate steps to let North Korea know that it can't threaten the safety and security of other countries with impunity."
Japan's chief Cabinet secretary, Takeo Kawamura, said the government is assuming this latest launch will go ahead as promised by North Korea despite international diplomatic objections.
Kawamura told reporters that the government is well aware Japanese are anxious and the public will learn of any information as soon as officials are informed.
Japanese diplomats said their government is likely to call for an emergency meeting of the U.N. Security Council immediately following the North Korean launch to discuss what punitive actions against Pyongyang should be pursued.