North Korea said it has finished preparations to launch a rocket carrying a satellite into space, and reiterated it is for peaceful purposes, Kyodo news agency reported on Tuesday.
The United States and its allies believe the long-range rocket launch, likely later this week, will give North Korea a chance to test ballistic missile technology.
Japan will discuss with other nations what actions to take in the event of a launch, Prime Minister Yoshihiko Noda said in an interview with a group of Japanese media.
He said the launch is a violation of a United Nations Security Council resolution, and Japan is asking North Korea to show restraint.
(Reporting by Mayumi Negishi and Kaori Kaneko; Editing by Edwina Gibbs)