Concerns have lingered over the Olympic and Paralympic Games amid a rise in COVID-19 cases in recent weeks in Japan, which led to the country introducing tougher restrictions to combat the spread of the virus.

An online petition calling for the cancellation of the Games has garnered more 300,000 signatures online since being established last week, while Tokyo is under a state of emergency until at least the end of the month.

Despite doubts over the Games, the IOC has welcomed encouraging remarks by the WHO.

Michael Ryan, executive director of the WHO Health Emergencies Programme, said organisers had worked "extremely hard" to manage risks around the event.

He highlighted the playbooks produced for the Games which aim to mitigate risks posed by COVID-19.

Ryan, speaking on Friday (May 7), had said that positivity rates in Japan were around seven per cent but had levelled off.

The WHO official expressed hope that a downward trend would continue and that the organisation was hopeful the Games could occur.

"There's been a tremendous amount of work done on the playbooks for the delegations and the teams that are coming, a lot of preparation amongst those teams regarding testing and quarantines and arrival and measures that have been taken in the Olympic villages, in the training facilities and around the venues themselves," Ryan said.

"Then there is the matter of attendance within the facilities themselves and I believe the Japanese authorities and the IOC still have not made final decisions regarding the level of attendance at those venues because of the variations in the incidence situation in Japan itself.

"We will leave it to the authorities in Japan, who are highly competent, to decide what level of attendance could occur in the Olympics."

"I've said the word mixing a number of times and we've said this again and again with this virus; this virus transmits in places where people mix in high density for prolonged periods of time," Ryan added.

"The aim of the protection around the athletes is to prevent that kind of contact and mixing and close proximity, to create an environment of safety for the athletes, to create and maintain a environment of safety for everyone who attends, whatever that proportion is, and to create an environment of safety around the venues themselves.

"Some of those decisions cannot be made until closer to the event because it will depend on the epidemiologic situation at that time, so it is not a failing at all on behalf of the organisers that they haven't made certain decisions because those decision can only be made on the basis of the epidemiologic parameters that pertain at that time.

"It is our hope that the Olympics can occur.

"Many other events - and we've seen sporting events and leagues run very, very safely over the last six months without spectators, with special bubbles and arrangements for athletes and for others, footballers and many, many others."

Ryan acknowledged that the Olympics were a complex event and said the Games would be a test of risk management and logistics.

He expressed confidence in Tokyo 2020 and the IOC to manage risks, as well as the final decision on the attendance of spectators at the Games.

IOC President Thomas Bach issued a statement which welcomed Ryan’s comments.

"These very encouraging remarks by the World Health Organization are a clear signal to everyone: the athletes, the delegations from all around the globe, the Organising Committee, all the Japanese people and also the IOC and IPC [International Paralympic Committee]," Bach said.

"I would like to express our thanks to WHO for the cooperation and advice we have enjoyed from them since the very beginning of the pandemic and the confidence they have expressed in the planned countermeasures and the IOC.

"We will continue to be guided by scientific and medical expertise from around the world to organise safe Tokyo 2020 Olympic and Paralympic Games for everyone.”

Tokyo 2020 will be among the topics for a short IOC Executive Board meeting tomorrow, which is expected to last for less than two hours.

The agenda will include discussion on the Olympic Virtual Series (OVS).

The first edition of the series was announced last month.

Five sports will be part of the inaugural OVS - baseball, cycling, rowing, sailing and motorsport - and it will run from Thursday (May 13) until June 23, ahead of the Tokyo 2020 Olympics.

Cycling and rowing will be virtual events, while baseball, sailing and motorsport will be esports events.

Olympic Agenda 2020+5 will also feature, with discussions expected on the topics of sustainability and legacy, gender equality and inclusion, as well as safe sport.