John Coates, chairman of the IOC's Coordination Committee for the Tokyo 2020 Olympics, told organisers on Monday that stakeholders may lose confidence in their ability to host the Games if they do not answer questions about preparations.
Speaking at the International Olympic Committee's Project Review meeting in Tokyo, Coates said there would be no let-up from National Olympic Committees (NOCs) and international sporting federations in the lead-up to the Games.
"We enter a phase where questions from stakeholders become very pragmatic and very urgent," said the Australian in his opening remarks ahead of the two-day meeting.
"I wasn't at SportAccord but I have read and I know that your delegation experienced this from the international federations that were there, with some very pertinent questions.
"I say this as a friend: you can expect more of this."
Over 200 NOCs will visit Tokyo in November and Coates expected it to be a challenging time for organisers.
"They are going to want answers and so you have to be prepared to answer these questions when they are raised. If you don't, these are the sorts of things that can impact the confidence of our stakeholders in your ability to host the Games," said Coates.
"That is very hard to come back from, once that momentum starts to build."
The Project Review meeting comes following a decision made in December to update the projected budget for Tokyo 2020, involving a reduction of $US1.4 billion ($A2.0 billion) in total costs.
Games organisers have been working to slash costs after a study in 2016 warned that expenses could balloon to four times the initial estimate made in the bid process.
The IOC is keen for Tokyo to set a good example by cutting costs in order to attract future candidate cities but Coates stressed that the second version of the budget was not solely about reducing costs.
"It is not just about saving you money. It is about a more efficient delivery of the Games and utilising the knowledge of your stakeholders.
"I hope, and I will stress this many times, that you approach it from that aspect, not just saving money."
Tokyo 2020 President Yoshiro Mori reiterated during his opening remarks that "budget reduction is the highest priority" for organisers.
