Thomas Maresca, Special for USA TODAY

TOKYO — Japanese Prime Minister Abe Shinzo and his ruling coalition retained a two-thirds majority in Sunday's national elections, an outcome he said shows support for a stronger military and a hard line on North Korea.

“I think the results reflected the voters’ preference for a solid political foundation and their expectations for us to push polices forward and achieve results,” Abe told public broadcaster NHK after exit polls predicted a landslide victory.

In unofficial results early Monday, Abe's conservative Liberal Democratic Party (LDP) and the ruling coalition won 312 seats in the 465-seat lower house of parliament, exceeding a two-thirds majority at 310, and other parties had 143 seats, NHK said. Final results may not be tallied until Monday.

A two-thirds supermajority gives Abe and his allies the ability to push through changes to Japan's pacifist constitution to allow a more robust, conventional military.

Abe made his strong military stance a key point in the campaign, calling the threat from North Korea one of the two crises facing Japan, along with its rapidly aging population.

The prime minister, who has already served nearly five years, called for the snap election in late September after North Korea fired its second ballistic missile over Japan in a month. Abe wants to reduce the restrictions on Japan's Self Defense Forces, because the military is constrained by the constitution imposed by the United States after World War II.

“This is an election to question how we can protect our people's lives and good living from North Korea's threats,” Abe said last week during a campaign rally.

Voter turnout Sunday appeared lower than the last general election in 2014, in part because Typhoon Lan lashed Japan on Sunday with heavy rains and winds of 100 mph. Tens of thousands of households were advised to evacuate.

As of 7:30 p.m. local time, turnout was 31.8%, down 5.9 points from the same time in the 2014 election, according to Japan’s Ministry of Information and Communications. However, early voting was up by 62.5% from 2014, with a record number of 21.5 million voters casting ballots in advance.

Even with a strong majority in parliament, Abe does not have a bulletproof mandate to push through his agenda. His popularity, which plummeted in recent months because of a corruption scandal in his Cabinet, has rebounded but still remains low despite his party’s success in this election.

A poll by the Asahi Shimbun newspaper on Wednesday showed that 51% of voters do not want Abe to continue as prime minister, while 34% said they did.

Working out the details and time frame for revising the constitution has already been a difficult political challenge and will remain so, said Tobias Harris, a Japan expert with Teneo Intelligence in Washington, D.C.

“I think he’s going to go ahead with (attempting to change the constitution),” Harris said. “But the obstacles that will be present tomorrow are the same obstacles that were present today and yesterday.”

Any change in the constitution to allow a stronger military must also be put to a referendum vote by the public, who remain sharply divided on the issue. The same Asahi poll showed that 37% supported Abe’s proposal for revising the constitution, while 40% oppose it.

More:North Korea crisis gives boost to Japanese Prime Minister Shinzo Abe before election

More:Japan PM Abe dissolves lower house, calls snap election

More:North Korea launches ICBM toward Japan for 2nd time this month

More:Trump commits to security of Japan

Abe’s LDP was able to take advantage of a fractured opposition for this election, as its traditional opponents, the center-left Democratic Party, disbanded in September.

Many members joined the Party of Hope, a political party formed by media-savvy conservative Tokyo governor Yuriko Koike. Other, more liberal members joined the new Constitutional Democratic Party (CDP).

The CDP, under the leadership of founder Yukio Edano, was too new to present much of a challenge in Sunday's vote, but may form a stronger opposition voice to constitutional reform, Harris said.

“In a short period of time, they've shown themselves to be pretty adept at using social media and getting volunteers,” he said. “If they're able to build on that, you now have a party that would lead the ‘No’ campaign when there is a referendum on a constitutional amendment, and that was not the case before.”

Sumizawa Akaru, 21, a musicology student in Tokyo, said he supported the CDP in this election partly because he felt that changing the constitution would lead to a greater threat of war.

“Abe is dangerous,” he said. “There is a need for defense, but we shouldn’t change (the Constitution).”