Patriot missile launchers -- at the ready in Tokyo.
On Saturday, Japan said it was firing up batteries like this following news that rival North Korea was planning a satellite launch.
Prime Minister Yoshihiko Noda said the rocket bearing the satellite could be shot down if it came near Japanese territory.
He also chastised the leaders of the isolated state.
(SOUNDBITE) (Japanese) JAPANESE PRIME MINISTER YOSHIHIKO NODA SAYING:
"If they do indeed go ahead with the launch, then it is indeed very regrettable. Not only our country but the entire international community must take strong measures to deal with this."
The announcement came just hours after North Korean state TV said Pyongyang was planning a rocket launch.
The rocket's path would carry it south over Japan, a similar trajectory to a failed launch in April.
The U.S. says the launch would be a provocative act. China has urged calm.
Japan readies defensive missiles (1:03)
Dec. 2 - Tokyo says its prepared to shoot down a North Korean rocket if it comes close to Japanese territory. Andrew Raven reports. ( Transcript )