Chief Cabinet Secretary Yasuo Fukuda remained wary Wednesday over a string of events indicating a possible softening of North Korea's stance toward Japan.
Fukuda said it was still premature to regard the overtures as genuine.
Tokyo and Pyongyang have no diplomatic ties, and the two sides have not held formal bilateral negotiations since August, when talks broke down over the handling of North Korea's abduction of Japanese during the 1970s and 1980s.