Tokyo 2020's new president Seiko Hashimoto on Thursday vowed to "regain trust" in the Olympic organising committee after an embarrassing sexism row, with just over five months until the virus-postponed Games.

Hashimoto, a seven-time Olympian, had been one of just two women in Japan's cabinet, serving as Olympic minister before stepping down to take the key post.

She replaces 83-year-old Yoshiro Mori, who resigned after saying women talk too much in meetings, sparking outcry in Japan and abroad.

"I'm sure the Games are going to attract more attention related to gender equality, and in this regard I am determined to regain trust, by my fullest endeavours," she said after her appointment.

She pledged to increase the number of women on the Tokyo 2020 executive board from around 20 percent to 40 percent, and urged Olympic torchbearers and volunteers who had quit in protest at Mori's comments to return.

Until Thursday, Hashimoto, 56, was also minister for gender equality and women's empowerment.

"I recognise that there is still a lot of conscious division of roles according to gender (in Japan). What can be done to change that through the organising committee's reforms is important," she said.

She had reportedly been reluctant to take on the job, and will face an uphill struggle to win over the public before the Games are due to open on July 23.

Anti-infection measures should be Tokyo 2020's "top priority", she said, pledging to work to "ensure that the public both domestically and abroad feel this is going to be a safe and secure Olympic Games".

Prime Minister Yoshihide Suga said Hashimoto's years as a sprint cyclist and speed skater -- winning bronze in 1992 -- would be good preparation.

"She has experience of competing at the summer and winter Olympics seven times. I want her to work hard to firmly realise the philosophy of the Tokyo 2020 Olympics and Paralympics by making use of that experience," he said.

Mori, a former prime minister, resigned after domestic and international outcry over remarks he made in early February to members of the Japanese Olympic Committee.

He apologised for the sexist remarks, while insisting he was repeating complaints made by others, but then dug a deeper hole when he explained that he "doesn't speak to women much".

Hashimoto submitted her resignation earlier Thursday to Prime Minister Yoshihide Suga
Hashimoto submitted her resignation earlier Thursday to Prime Minister Yoshihide Suga JIJI PRESS / STR

But Hashimoto is not without baggage and has also been involved in controversy -- facing a sexual harassment scandal in 2014 after photos emerged of her hugging and kissing a male figure skater over 20 years her junior.

The skater said he did not think he had been harassed by the married Hashimoto, who apologised at the time for any "misunderstanding" caused by the photos.

"My actions seven years ago were deeply regrettable... I am still reflecting about what I did," Hashimoto said after her appointment on Thursday.

Hashimoto's nomination comes after Mori's attempt to handpick his successor -- he proposed an 84-year-old ex-footballer -- was nixed following public criticism.

A selection panel with a 50-50 gender split was formed to find the new president, with Hashimoto immediately among the leading candidates.

"The fact that they established five criteria to choose the new president -- which included an understanding of gender equality and human rights -- represents real progress," said Kazuko Fukuda, a campaigner for women's sexual and reproductive rights.

"But it's about making sure the country's gender policies don't take a step back from now on," she warned.

"Having won a medal, participated in seven editions of the Olympic Games and the Olympic Winter Games, and having led Japan's delegation to the Olympic Games multiple times, she is the perfect choice for this position," said IOC president Thomas Bach.

"She will ensure that the focus in the final months of preparation remains on the athletes' experience while planning all the necessary Covid-19 countermeasures."

Tennis superstar Naomi Osaka, a leading face of the Games in Japan, welcomed Mori's resignation and his replacement by Hashimoto.

"I feel like it's really good because you're pushing forward, barriers are being broken down, especially for females," she said.

But challenges lie ahead for Hashimoto, with polls showing around 80 percent of people in Japan back either cancellation or further postponement.

Organisers have tried to quell the disquiet by releasing virus rulebooks -- but doubts persist, with Tokyo and other regions currently under a Covid-19 state of emergency.

The first Olympic test event of 2021 has already been postponed because of tightened border restrictions under the measures.