Competitors at this year's Tokyo Olympics and the 2022 Beijing Winter Games will be offered coronavirus vaccines bought from China, Olympic chief Thomas Bach announced Thursday.

The Chinese Olympic Committee have made "an offer to make additional vaccine doses available to participants for Tokyo 2020 and Beijing 2022", Bach said.

"The IOC will pay for these additional doses of vaccines for the Olympic and Paralympic teams.

"The IOC will also pay for two doses more that can be made available to people in that country," in what Bach said was a "demonstration of solidarity" in the fight against the Covid-19 pandemic.

Bach said the Chinese Olympic Committee, in cooperation with the IOC, was ready to make vaccine doses available in two ways.

"This can be via international partners or in countries where partnerships are already in place with the Chinese government," he said.

Bach added that a significant number of Olympic teams "have already been vaccinated."

"Another significant number have received a commitment from their governments or are in very positive discussions."

Bach also tried to play down risks to Japan from hosting the Olympics, citing the fact that 270 world championships had been held involving more than 30,000 athletes following "rigorous health and safety protocols" since September 2020.

"Not a single one of these events turned into a virus spreader," Bach said, adding they had posed no danger to host communities: "It's clean and obvious proof."

The Tokyo Games were originally scheduled for the summer of 2020, but it was pushed back by one year as the coronavirus pandemic raged across the globe.

They are now scheduled for July 23-August 8, Bach at pains to reiterate that the IOC remains committed to holding a "successful and safe" Games this year, dismissing cancellation talk as "speculation".

Overseas spectators, however, are likely to be shut out, as Japanese organizers prioritize public health and safety. (AFP)