Tokyo reacted with concern Tuesday to news that North Korea has suspended its search for missing Japanese believed to have been abducted by North Korean agents in the 1970s and 1980s.

"I think it was a move that lacks in sincerity," Prime Minister Junichiro Koizumi told reporters Monday evening. "It's deplorable."

Koizumi noted that the government will use all possible means and channels to urge Pyongyang to deal "more earnestly" with the issue.

"It was regrettable," Chief Cabinet Secretary Yasuo Fukuda said. "The government will continue to seek action by the North Korean side, based on our belief that (the abductions) are an important issue that concerns the safety of Japanese people."

Asked about the impact the announcement would have on efforts to normalize relations, Fukuda said it will depend on the course of action North Korea chooses.

"We will follow whatever moves the North Korean side makes," he said.

Tokyo maintains that at least 10 Japanese were abducted by North Korean agents in seven incidents through the 1970s and 1980s. Although North Korea denies this, it had promised to search for the Japanese as missing persons.

The issue is one of the biggest barriers to normalizing bilateral ties.

Pyongyang's official Korean Central News Agency quoted the North Korean Red Cross on Monday as announcing that it has suspended its investigation of missing Japanese nationals.

It said "the Japanese side's fuss about 'kidnapping' has done harm to the dignified DPRK (North Korea) and extremely provoked the Korean people, thus creating great difficulties in the investigation into the 'missing persons.' "

Based on police investigation records, the Japanese government has concluded that at least 10 Japanese may have been kidnapped from Japan on seven separate occasions in the 1970s and 1980s and taken to North Korea.

North Korea, which has categorically denied the abductions, agreed in 1999 to investigate the fate of the missing Japanese.

Foreign Minister Makiko Tanaka, who told reporters Tuesday that she has not officially confirmed the report because Japan and North Korea have no diplomatic relations, said it would be regrettable if the report was true.