Shinzo Abe is on course for a resounding victory in Japan's snap election – and has vowed to "deal firmly" with North Korea.
A projection by private broadcaster TBS gave the incumbent PM's conservative coalition 311 seats in the 465-seat parliament – putting Mr Abe on course to become Japan's longest-serving leader.
The victory is likely to strengthen Mr Abe's resolve to tackle North Korea's nuclear threat after it fired two missiles over Japan in a month.
Mr Abe, 63, whose country is a key US ally in the battle to rein in Pyongyang, said: "As I promised in the election, my imminent task is to firmly deal with North Korea. For that, strong diplomacy is required."
According to the top-selling Yomiuri daily, Mr Abe was set for a "landslide win" as his gamble to hold a snap election appeared to pay off.
However, it was not clear whether his coalition would retain its two-thirds "supermajority," requiring 310 seats, as some media had it falling just short.
A "supermajority" would allow Mr Abe to propose changes to pacifist Japan's US-imposed constitution that forces it to renounce war which limits its military to a self-defence role.
Mr Abe said he would "deepen" debate on the divisive issue in parliament and said: "I don't plan to propose changes via the ruling bloc alone. We'll make efforts to gain support from as many people as possible."
The vote came as torrential rain and severe winds from Typhoon Lan battered the country, forcing many to vote early.
Mr Abe's Liberal Democratic Party (LDP) benefited from the weakness of the two opposition parties being formed just weeks before polling day.
Support fizzled out for the Party of Hope founded by popular Tokyo Governor Yuriko Koike and it was on track to win around 50 seats, the TBS projection suggested.
Speaking from Paris where she was attending an event in her capacity as leader of the world's biggest city, Ms Koike told public broadcaster NHK she feared a "very severe result".
She added: "As the person who launched the party, I will take responsibility."
The new centre-left Constitutional Democratic Party performed slightly better than expected, but still trailed far behind Mr Abe with 58 seats.
The economy and the global crisis over North Korea dominated the 12-day campaign.
North Korea has threatened to "sink" Japan into the sea and became embroiled in a war of words with US President Donald Trump.
Mr Abe took a hard-edged stance throughout the campaign and insisted that Japan "would not waiver" despite increasing belligerence from Pyongyang.
The economy became a priority for many voters who feel Mr Abe's growth policy has left them behind.
Pensioner Hideki Kawasaki, 67, said: "Neither pensions nor wages are getting better … I don't feel the economy is recovering at all."