There will be no Formula One races held in Azerbaijan, Singapore or Japan in 2020, it has been confirmed.
The F1 season was halted in March before it was even able to begin due to the coronavirus pandemic, with the Australian Grand Prix curtailed at short notice after a member of the McLaren garage tested positive for COVID-19.
A new, revised calendar was confirmed at the start of June, with eight events outlined between July 5 and September 6.
The F1 authorities were hopeful of adding further events to the schedule, but races in Singapore, Azerbaijan and Japan will not be considered.
A statement issued by F1 on Friday read: "As a result of the ongoing challenges presented by COVID-19, we and our promoters in Azerbaijan, Singapore and Japan have taken the decision to cancel their races for the 2020 season.
"These decisions have been taken due to the different challenges our promoters face in those countries. In Singapore and Azerbaijan the long lead times required to construct street circuits made hosting the events during a period of uncertainty impossible and in Japan, ongoing travel restrictions also led to the decision not to proceed with the race.
"At the same time we have made significant progress with existing and new promoters on the revised calendar and have been particularly encouraged by the interest that has been shown by new venues in hosting a Formula 1 race during the 2020 season.
"We appreciate this is still a time of uncertainty and complexity around the world and will continue to ensure we proceed with the 2020 season in a cautious and flexible way. We have detailed and robust safety plans in place to ensure we begin our season in the safest possible way."
Formula One remains confident between 15 and 18 races will eventually be confirmed for the season, with a completed calendar predicted to be published before the campaign gets under way in Austria next month.
Should further locations become implausible, F1 motorsports chief Ross Brawn suggested an extended European season could be an option.
Brawn said: "Things are moving fast, but we still have time. We have lots of different options and we're very confident we're going to have a great second half of the season.
"There is a contingency to have an extended European season with another one or two races if needed. I think Bahrain and Abu Dhabi will be the backstop of the season from what we can see at the moment. That gives us 10. We'll find at least five or six good races in the middle."
Among the other tracks being considered are Mugello, Imola, Portimao and Hockenheim.