Prime Minister Taro Aso kicked off a campaigning tour ahead of this month's general election on Saturday by focusing on the issue of kidnappings of Japanese citizens by North Korean agents during the Cold War.
Aso went to a coastal area in Niigata, north of Tokyo, where a schoolgirl was snatched by Pyongyang agents three decades ago.
"We have to take stern action" on the issue, Aso was quoted by Jiji Press as telling reporters after he was briefed by local police officials about how Megumi Yokota was kidnapped in 1977.
The issue of the kidnappings has whipped up anti-Pyongyang sentiment among Japanese and Japan has demanded North Korea return all abductees, including Yokota.
The communist regime has admitted it abducted 13 Japanese to train its spies. It allowed five to return home but said the others had died.
Aso's Liberal Democratic Party (LDP), which has ruled Japan almost without a a break for more than half a century, is lagging badly in opinion polls against the untested centre-left Democratic Party of Japan (DPJ) ahead of the August 30 poll.
"What party do you think can protect this country and people's life? Please make a judgement based on policies," Aso said in a speech in central Niigata later Saturday.
In his party's election campaign pledges unveiled on Friday, Aso promised to fix the recession-hit economy and create millions of jobs.
Approval ratings for Aso, a political veteran with a gruff demeanour, often derided for his gaffes and erratic policy changes, have dipped into the teens, according to recent opinion polls.
The DPJ also accused North Korea over the kidnappings in its own campaign pledges, saying it would do its "utmost" to resolve the issue.