will need to make it ready for firing," one of the sources said.

Earlier in the day, Chief Cabinet Secretary Shinzo Abe said Japan remains on alert, expecting Pyongyang to fire more missiles, although an immediate Taepodong-2 seemed unlikely.

In remarks apparently directed to North Korea's allies China and Russia, Abe told reporters: "U.N. Security Council members, especially those with permanent seats, must realize this is an extremely grave issue and they must make sure they aren't seen as being sympathetic to North Korea.

"We cannot say for sure that no more missiles will be fired. The danger of another launch cannot be ruled out," the top government spokesman said.

In a special lecture at the Yomiuri International Economic Society later Thursday, Abe said what has been widely reported -- that Pyongyang test-launched its ballistic missiles to pressure the United States to start bilateral talks.