With the coronavirus pandemic threatening the holding of the re-arranged Tokyo Olympics, IOC chief Thomas Bach is expected on Wednesday to set out how a "safe" Games could be organised and respond to growing questions on vaccinating competitors.
The International Olympic Committee said on Tuesday, ahead of a meeting of its executive board, that it was determined the Tokyo Games will go ahead and that they would be "safe and secure".
While it urged participants to be vaccinated, the IOC said that was only part of its Covid-19 "toolbox".
The Games were originally scheduled for last summer but were postponed in the face of the first wave of the coronavirus pandemic, becoming the first Olympics to suffer that fate in peacetime.
The IOC and Japanese organisers rescheduled the Games for July 23 to August 8 this year.
But several media reports have claimed that the Games cannot go ahead, with British newspaper The Times last week quoting an unnamed source in Japan's ruling coalition as saying "the consensus is that it's too difficult" to hold the Olympics.
That claim was rejected by the Japanese government, with a spokesman saying there was "no truth" to the report.
After the last executive board meeting, the IOC released a statement on December 12, the same day the Pfizer vaccine was approved in the United States, expressing its "full commitment" to staging the Games.
Since then, the emergence of more infectious strains and the problems of global vaccination have sparked debate on whether the Games can take place, and the ethics of allowing participants to jump the vaccination queue.
Japan declared a state of emergency on January 7. The host country, where a quarter of the population is over 65 and 12.5 percent are over 75, reportedly does not plan to start mass vaccinations until May.
Bach has said there would be "neither a vaccine obligation nor a priority to athletes" for the Games.
- Questions around vaccines -
The head of France's Olympic Committee, Denis Masseglia, said this week that "for legal reasons" the IOC could not make vaccination obligatory even if it wanted to.
While Tuesday's statement repeated that vaccination "will not be obligatory", it also said the IOC wished "to encourage and assist their athletes, officials and stakeholders to get vaccinated in their home countries...before they go to Japan."
"This is to contribute to the safe environment of the Games, but also out of respect for the Japanese people."
The statement was careful to stress the IOC did not want athletes to receive vaccine priority.
"Vaccines are one of many tools available in the toolbox, to be used at the appropriate time and in the appropriate way," it said.
It added that other "countermeasures" included "immigration procedures, quarantine measures, testing, personal protective equipment, contact tracing."
That array is likely to discourage athletes from travelling to Tokyo without being vaccinated.
Britain's quadruple Olympic gold medallist runner Mo Farah said on Tuesday that athletes had been told they will be vaccinated before going to the Games.
"What they have said to us is basically everyone will be able to get Covid injections and after that it's less risk of spreading the disease, and then from there just see what happens and take one day at a time," Farah told radio station talkSPORT.