Japanese Prime Minister Shinzo Abe pledged Monday to work with the US, China and Russia to contain North Korea's nuclear threat with "strong, resolute diplomacy", as he "humbly" accepted his landslide victory in a snap election.

Fresh from clinching a two-thirds "super-majority" that enables the nationalist premier to realise his dream of revising Japan's pacifist constitution, Abe vowed to forge a "national consensus" on the divisive issue.

Addressing reporters on his election win, Abe said he would "confirm close co-operation" on North Korea with Donald Trump when the US president visits Japan next month and then discuss the issue with the Chinese and Russian leaders.

"I have renewed my determination to secure people's lives and peaceful living, no matter what," said the 63-year-old.

North Korea, which has threatened to "sink" Japan and fired two missiles over its northern islands, dominated the 12-day election campaign that Abe eventually won comfortably.

"We will solve North Korea's missile, nuclear and abduction issues with strong, resolute diplomacy," he said in reference to the abduction of Japanese by Pyongyang in the 1970s and 1980s.

Abe's conservative coalition was on track to win at least 313 seats with only a handful left to call, according to public broadcaster NHK, giving him the coveted two-thirds majority in the lower house of parliament.

He is now on course to become Japan's longest-serving premier, winning a fresh term at the helm of the world's third-biggest economy and key US regional ally.

North Korean belligerence helped the ruling coalition because "people are scared" and voted for Abe's hardline stance, said Gerald Curtis, professor of political science at Columbia University.

"I focused on the national defence issue, because I am concerned about North Korea. So I chose the party that will work firmly on this issue," one voter, 66-year-old pensioner Tsuyoshi Ushijima, told AFP.

- 'Some concerns' about Abe -

However, while local media acknowledged what was described as a landslide victory, many attributed Abe's win to a weak and ineffective opposition and urged caution.

"The voters didn't think the opposition parties were capable of running a government... they chose Prime Minister Abe, who is at least better, even if they had some concerns about the ruling coalition," said the Nikkei daily.

The Asahi newspaper said: "The Abe brand is not as strong as it was before. There are some signs that voters are seeking a change in the situation whereby Abe is the only decent option."

According to an exit poll by Kyodo News on Sunday, 51 percent of voters said they do not trust Abe with 44 percent saying they did.

Turnout was expected to be only a fraction higher than the all-time low in the 2014 election. It was boosted largely by people voting early to avoid a typhoon, which smashed into Japan on election day.

The opposition Party of Hope, formed only weeks before the election by the popular Tokyo Governor Yuriko Koike, suffered a drubbing. It won just 49 seats according to the NHK projections.

A chastened Koike, speaking thousands of kilometres away in Paris where she was attending an event in her capacity as leader of the world's biggest city, said it was a "very severe result" for which she took full responsibility.

The new centre-left Constitutional Democratic Party out-performed Koike's new group but still trailed far behind Abe with 55 seats.

"People are reluctant about Prime Minister Abe, but then who would you turn to? There is no one," said Naoto Nonaka, professor at Gakushuin University in Tokyo.

- 'Deepen constitution debate' -

Abe, who has in the past been criticised for arrogance towards voters, vowed to face the challenge posed by the victory "humbly."

He struck a cautious note on possible revisions to the US-imposed constitution, saying he would "deepen" debate in parliament on the divisive issue but not seek to ram anything through.

Any changes to the document must be ratified by both chambers of parliament and then in a referendum, with surveys showing voters are split on the topic.

"Abe would want to see a constitutional revision but we know he is ideologically on the right and he's very pragmatic at the same time. And I think that pragmatism will force him to back off from pushing that issue too hard," said Curtis.

Many voters stressed that the economy is their biggest concern. The prime minister's trademark "Abenomics" strategy of ultra-loose monetary policy and huge government spending has failed to rekindle the former Asian powerhouse.

But investors cheered the victory, with the benchmark Tokyo index up 1.11 percent, extending a winning run that has seen 15 straight consecutive gains for the first time in its near 70-year history.

Source:AFP