They should have begun on 24 July but were postponed in March because of Covid-19 and are now due to be held from 23 July to 8 August next year.
IOC president Thomas Bach said there were "all different countermeasures" but hoped spectators would be allowed.
He said an Olympics behind closed doors "is clearly something we don't want."
Many sports at professional level have resumed without fans in attendance to avoid the sort of mass gatherings which can lead to increased transmission of the coronavirus.
"We are working for a solution which on the one hand is safeguarding the health of all the participants and on the other hand is also reflecting the Olympic spirit," Bach said.
Meanwhile, the Youth Olympics in Senegal scheduled for 2022, have been put back to 2026.
Bach explained that the fourth edition of the Youth Games was postponed as a result of the "financial consequences" of the current "global health crisis".