Bach said the IOC was "counting on" European National Olympic Committees (NOCs) to make sure the guidelines and rules are "fully respected" during the delayed Tokyo 2020 Olympics, set to open in 42 days' time.

A total of 50 NOCs from the continent are expected to send athletes to the Games, pushed back to this year because of the COVID-19 crisis.

Organisers and the IOC have warned athletes the Olympics and Paralympics in the Japanese capital will be different to previous Games owing to the rules that will be implemented, while the events could also be held without spectators.

Athletes have been told to arrive no earlier than five days before their event and leave a maximum of two days after as part of plans to reduce the number of people inside the Village.

All participants have been barred from attending bars and restaurants, and will be subjected to frequent testing for COVID-19, as detailed in the playbooks for the Games.

The third edition of the playbooks, designed to ensure the Games can take place safely despite the pandemic, is set to be published next week.

"European NOCs will bring a significant number of athletes to Tokyo, so we are counting on you to ensure the guidelines and rules are fully respected," Bach said during a video message to the European Olympic Committees General Assembly in Athens.

"In this way, you can lead by example."

The IOC and Tokyo 2020 have faced mounting criticism for pressing ahead with organising the Games but have insisted the event will be "safe and secure" amid a backdrop of rising public opposition.

The IOC said this week that it expects 80 per cent of people inside the Athletes' Village to have either been vaccinated or be in the process of being inoculated before the Olympic Opening Ceremony on July 23.

A decision on whether fans will be able to attend the Games is due to be made by the end of the month.

Foreign spectators have already been banned due to the pandemic.