Tokyo 2020 organisers are "extremely confident" their plans for the rescheduled Olympic Games are on track but will not confirm final details until June due to the unpredictability of coronavirus.

Information about the event, which will run from July 23 to August 8, is being released in a series of 'playbooks', which guide stakeholders about their responsibilities during their stay in Japan.

Olympic Games executive director Christophe Dubi said there had been resounding support for the initial playbook following its publication a fortnight ago.

Further versions are due to be available in April and June and, while Dubi acknowledges the imminent desire for greater detail, he believes uncertainty caused by the global pandemic means it is better to wait and avoid "regret".

"It was always the case that there would be further versions of it (the playbook). We have to have timely decision-making for some of the items," he said.

"I get that people will want to have as much possible details but, at the same time, if we make a number of decisions now where the situation regarding Covid is very fluid then we might regret some of the decisions.

"It's very important to look at the way the pandemic evolves, consider the situation at any given point in time, and make the right call at the right point in time.

"The right point in time, as far as we're concerned, is April for the second version of the playbook and for the final details, with everything down to the last wire, bolt and notch, will be in June.

"This is the sequence we have and we are extremely confident with that sequence."

Dubi spoke following three days of joint working meetings on Covid-19 countermeasures, which featured officials from the International Olympic Committee, the International Paralympic Committee (IPC) and Tokyo 2020.

Wednesday's press conference coincided with the start of coronavirus vaccinations in Japan.

IPC chief marketing and communications officer Craig Spence was heartened by that development.

"I think it's encouraging that today the vaccinations started in Japan," he said.

"By Games time, at least a billion people will have been vaccinated around the world, so that's good progress and can only be seen as a positive when it comes to Games preparations.

"This time last year there was no plan to stage the Games during a pandemic – today there is.

"I think the coming months will possibly present challenges for us.

"We're treading new ground and effectively we are having to reinvent how the Games will go."