Tokyo 2020 organisers were poised to name Olympic Minister Seiko Hashimoto their new president on Thursday after previous chief Yoshiro Mori resigned over a sexism row.
Hashimoto submitted her resignation early Thursday afternoon to Japanese Prime Minister Yoshihide Suga, ahead of the day's second meeting of Tokyo 2020's executive board -- widely expected to announce her appointment.
She said Suga had offered "kind words", saying he hoped she would "give all my strength to create a Tokyo Games that will be embraced by the Japanese people."
She declined to comment further on her expected appointment or her plans for the job until her new role is official.
A seven-time Olympian and one of just two women in Suga's cabinet, Hashimoto has been among the frontrunners for the Tokyo 2020 job since Mori stepped down last week.
She will take on the role just over five months before the virus-postponed Games are scheduled to open, facing public scepticism about whether the event can be safely held in a pandemic.
A committee with a 50-50 gender split was formed to find a successor to 83-year-old Mori after he stepped down last Friday following uproar over his claims that women speak too much in meetings.
Tokyo 2020's executive board met earlier Thursday to hear the results of the committee's deliberations with 2020 vice-president Toshiaki Endo saying a quick decision was needed.
Mori's departure was "enormously damaging from the viewpoint of preparation five months before the Games," Endo said.
"We need to make a decision on the new president as soon as possible, though it is necessary that it goes through appropriate procedures, given the issue has attracted attention at home and abroad," he added.