Japanese Prime Minister Shinzo Abe says he will dissolve the lower house of parliament and call fresh elections in October.

Abe said at a news conference on Monday that he would dissolve the more powerful house in Japan's two-chamber parliament on Thursday when it convenes after a three-month summer recess.

"I will dissolve the House of Representatives on the 28th" of September, Abe told reporters, a precursor to a general election.

The prime minister did not give a date for the election, but local media reported it would likely take place on October 22.

READ MORE: Abe denies favours for friend Kake amid falling support

Surveys suggest voters approve of the hardline stance taken by the nationalist Abe on North Korea, which fired two missiles over the country within a month and has threatened to "sink" Japan.

According to a weekend poll in business daily Nikkei, 44 percent of voters plan to vote for Abe's conservative Liberal Democratic Party (LDP), while only eight percent favoured the main opposition Democratic Party.

Nevertheless, one-fifth of those polled said they were still undecided, potentially opening the door for gains by a new party formed by allies of the popular mayor of Tokyo Yuriko Koike, which will field dozens of candidates.

Koike's Tomin First no Kai (Tokyo Residents First) party humiliated Abe and the LDP in local elections in July, but analysts say the new grouping has not had time to lay a national foundation that can mount a serious challenge to the prime minister.

In an apparent bid to steal Abe's limelight, Koike went before the cameras just hours before his announcement to announce she was creating a national political party called "Kibo no To" (Party of Hope).

"Japan is facing a difficult time considering the situation in North Korea. Economically, the world is making a big move while Japan's presence is gradually declining," said Koike.

"Can we continue letting (the existing lawmakers) handle politics?"

READ MORE: North Korea missile test angers Japan, South Korea

But Jeff Kingston, director of Asian Studies at Temple University in Japan, said there was "no opposition worthy of the name in Japan".

The winner of the expected snap election faces a daunting in-tray of challenges ranging from an unprecedented crisis with North Korea to reviving the once world-beating Japanese economy.

In addition to threats to destroy Japan, Pyongyang has fired two missiles over the northern island of Hokkaido in the space of less than a month.



However, the North Korea crisis appears to have given the hawkish Abe a welcome boost in the polls following a series of scandals, including allegations he improperly favoured a friend in a business deal.

Abe, the third generation of a powerful political family, appeared to be groomed for power from an early age. He was the country's youngest prime minister when he first won the top job.

Abe was the first world leader to cultivate close relations with US President Donald Trump, meeting the tycoon in Trump Tower even before he was inaugurated.