Kishida promised action on COVID-19 resurgence and to counter China in the region.
Fumio Kishida, Japan's former foreign minister, is set to become the country's next prime minister after winning a vote to lead the ruling Liberal Democratic Party.
Kishida will replace the outgoing party leader and prime minister, Yoshihide Suga, who is stepping down after serving only one year.
Kishida is certain to be elected the next prime minister on Monday in parliament, where the LDP and its coalition partner control both houses.
He has vowed to tackle "national crises” including COVID-19 and the pandemic-battered economy after his predecessor, Suga, was criticised for allowing the Tokyo Olympics to go ahead this year despite surging infection rates.
He also said he would pursue “important issues related to Japan's future” through a vision of “a free and open Indo-Pacific” that counters China's assertiveness in the region.
Kishida defeated the popular vaccinations minister, Taro Kono, in a runoff after finishing only one vote ahead of him in the first round, in which none of the four candidates, including two women, was able to win a majority.
In a landslide 257-170 victory in the second round, Kishida received support from party heavyweights who apparently chose stability over change advocated by Kono, known as a maverick and a reformist.
The long-ruling conservative Liberal Democratic Party desperately needs to quickly turn around plunging public support ahead of lower house elections coming within two months.
The 64-year-old former foreign minister was once seen as an indecisive moderate. Lately, however, he has shifted to become a security and diplomatic hawk as he sought support from influential conservatives to win the party election.
Kishida has called for a further increase in Japan’s defense capability and budget and vowed to stand up to China in tensions over self-ruled Taiwan that China claims as part of its territory, and Beijing’s crackdown on dissent in Hong Kong.