While Japan remained on high alert Monday for North Korea's "satellite launch," Pyongyang extended the launch window by a week to Dec. 29 because of a "technical deficiency," the Korean Central News Agency said.

KCNA quoted an unnamed spokesman for the Korean Committee of Space Technology as saying scientists and technicians were "pushing forward the preparations for the launch of the second version of Kwangmyongsong-3, a scientific and technological satellite, to a final phase."

"They, however, found technical deficiency in the first-stage control engine module of the rocket carrying the satellite and decided to extend the satellite launch period up to Dec. 29," the spokesman was quoted as saying.