TOKYO (AP) — Japanese Prime Minister Shinzo Abe has been re-elected as head of his ruling Liberal Democratic Party in a landslide, paving the way for up to three more years as the nation's leader.

Abe handily defeated his sole challenger, Shigeru Ishiba, a former defense minister.

Thursday's decisive victory may embolden him to pursue his long-sought revision to Japan's U.S.-drafted pacifist constitution, although the hurdles remain high and doing so would carry political risks.

The 63-year-old Abe has been prime minister since December 2012. He has cemented control of his party and received support from conservatives for bringing stability and continuity to economic and diplomatic policies. With a third term as party leader, Abe is poised to become Japan's longest-serving leader in August 2021.