Prime Minister Yoshiro Mori's remarks Friday that a secret proposal was made to North Korea in 1997 over the alleged kidnapping of Japanese nationals by Pyongyang have baffled the Foreign Ministry and drawn criticism both from the opposition camp and leading members of the ruling coalition.

Naoto Kan, secretary general of the largest opposition Democratic Party of Japan, denounced the remarks Mori made during his talks with British Prime Minister Tony Blair on the sidelines of the Asia-Europe Meeting in Seoul.

"This is a very imprudent act. Making comments like that could endanger Japan's national interests," Kan told reporters. "Maybe the prime minister is impatient, being driven by a desire to gain fame" by swiftly resolving the kidnapping issue, he said.