Shinzo Abe confirmed on Sunday he would run in his ruling party's leadership election, putting him on track to become Japan's longest-serving premier and bolstering his dream of reforming the constitution.
Abe is expected to be re-elected head of the conservative Liberal Democratic Party (LDP) easily, with the vast majority of lawmakers behind him and only one challenger, former defence minister Shigeru Ishiba.
"I have decided to lead Japan as the LDP leader and the prime minister for three more years, and with this determination I will run for the leadership election next month," Abe said in a press conference broadcast live from western Kagoshima prefecture.
Winning the September 20 run-off would effectively keep the hawkish Abe in power for another three-year term at the helm of the world's third-largest economy, with no real political party opposition to speak of.
Lawmakers make up 50% of the deciding votes, with the LDP's rank-and-file members accounting for the other half.
Abe said on Sunday that he would focus on the demographic issues raised by Japan's rapidly ageing society as well as pay attention to "the tumultuous changing international situation".
His rival Ishiba has similarly said that demographic concerns and the regional security threat from nuclear-armed North Korea are the two biggest challenges facing Japan.
Abe took power in December 2012 after a landslide general election victory for the LDP, making a dramatic comeback after a bowel ailment forced him to resign the premiership in 2007 following a year in the role.
Currently the longest serving Japanese prime minister is Taro Katsura, who served as premier thrice in the period between June 1901 to August 1913.
If Abe wins the leadership election and serves beyond November next year, completing more than 2,886 days as premier including his 2006-2007 term, he will be the longest serving prime minister in the country's history.