Satoru Arai, director of the Tokyo Medical Association, told Reuters it was "impossible" to envisage doctors and nurses volunteering at the rescheduled Games during the global health crisis.

Last March, the Tokyo 2020 Organising Committee and the Tokyo Metropolitan Government reportedly asked the association to sign up 3,500 health workers for the Games.

But with hospitals under increasing pressure due to the pandemic, Arai does not believe medical staff will have the time to support the Games on top of treating COVID-19 patients.

"No matter how I look at it, it’s impossible," Arai told Reuters.

"I’m hearing doctors who initially signed up to volunteer say there’s no way they can take time off to help when their hospitals are completely overwhelmed."

Last week, Japan's Olympic Minister Seiko Hashimoto said the country's Government was planning to secure thousands of medical staff for the Games.

"We are trying to secure necessary medical staff of around 10,000, on the premise of asking doctors and nurses that each of them work about five days during the Games period," said Hashimoto.

According to Tokyo 2020 President Yoshirō Mori, a decision over whether fans will be permitted to attend the Games will be made in March.

But Toshio Nakagawa, President of the Japan Medical Association, claimed it would be "impossible" to admit to hospital spectators that had contracted the virus at the event.

Arai also felt there would be less burden on providing medical staff should the Olympics take place behind closed doors.

He claimed his association had also not received any detailed information from Tokyo 2020 organisers on their plans.

"We got worried and reached out to the Olympic Organising Committee at the end of last year, asking what the plan was," added Arai.

"But we still haven’t heard anything."

A state of emergency was declared in Tokyo and 10 other prefectures last month in a bid to curb a surge in coronavirus cases.

With the infection rate remaining high, the Japanese Government extended the strict measures imposed on those areas until March 7.

Last week, 73 per cent of hospital beds available in the Japanese capital for coronavirus patients were full.

The situation has raised further question marks over the stage of the Games this year, while public support of Tokyo 2020 appears to be dwindling.

But the International Olympic Committee, the International Paralympic Committee and Tokyo 2020 remain steadfast in their belief the Games will go ahead as planned despite the COVID-19 crisis.

Tokyo 2020 was postponed to 2021 as a result of the pandemic, with the Olympics scheduled from July 23 to August and the Paralympics set to follow from August 24 to September 5.