Debate is set to intensify among the candidates to lead Japan's main ruling party. The winner is virtually assured of replacing outgoing Prime Minister Suga Yoshihide at the helm of the government.
There will be at least three people running in the Liberal Democratic Party's presidential election later this month. Official campaigning starts next Friday.
Regulatory Reform Minister Kono Taro formally announced his bid on Friday. Former LDP policy chief Kishida Fumio and former Internal Affairs Minister Takaichi Sanae have already entered the race.
Kono, who also serves as the minister in charge of Japan's coronavirus vaccine rollout, vowed to advance preparations for booster shots. He also said he will promote the use of digital technology.
Attention is focused on the candidates' economic and energy policies.
Kono said nuclear power plants that have been deemed safe will be allowed to operate. He has previously said Japan should phase out nuclear power.
Kishida is calling for a new type of capitalism based on a beneficial cycle of growth and wealth distribution. He will also propose the formation of a health crisis agency to oversee the response to the pandemic.
Takaichi says she will aim to realize stable consumer prices within an inflation target of 2 percent. Regarding energy, she has previously said that smaller-scale nuclear reactors could ensure a stable supply of electricity.
Former LDP Secretary-General Ishiba Shigeru is considering whether to join the race. In a blog post on Friday, he said he will listen to what the three candidates say before making a decision.
LDP Executive Acting Secretary-General Noda Seiko is currently seeking the 20 endorsements needed to run.