Four more of this year's Grand Prix have been cancelled by organisers because of the coronavirus pandemic.
Formula One has called off races in the US, Mexico and Brazil, countries that have among the worst infection rates in the world.
Officials have accepted that it will be impossible to hold the races, meaning there will be none in the Americas this year.
A race in Canada, originally due to be held in June and then postponed, has now been cancelled as well.
:: Listen to the Daily podcast on Apple Podcasts , Google Podcasts , Spotify , Spreaker
Dates have been added in Germany, Italy and Portugal in a revised 13-race season but organisers say they expect to have between 15 to 18 races in all, ending in the Gulf region in mid-December.
F1 said in a statement it will not be possible to race in Canada, USA, Mexico and Brazil this season "due to the fluid nature of the ongoing COVID-19 pandemic , local restrictions and the importance of keeping communities and our colleagues safe".
The Canadian GP in Montreal was due to be on 14 June and was originally postponed, while races in USA (Austin), Mexico (Mexico City) and Brazil (Interlagos) were set for 25 October, 1 November and 15 November.
Chase Carey, Chairman and CEO of Formula 1, said: "We are pleased that we continue to make strong progress in finalising our plans for the 2020 season and are excited to welcome Nurburgring, Portimao and Imola to the revised calendar."
They said final details of the calendar will be unveiled in the coming weeks.
The US reached an unwelcome milestone on Thursday, passing more than four million confirmed coronavirus cases, while more than 144,000 people have died after catching the illness there.
The number of cases in US states such as Texas and Florida have surged, prompting some governors to re-impose lockdown measures after easing them earlier in the summer.
Brazil has recorded more than 2.2m cases and suffered more than 84,000 deaths.
Almost 42,000 people in Mexico have lost their lives after becoming infected, from a total of more than 370,000 cases, according to Johns Hopkins University which is tracking the global spread of the virus.
Britain's Lewis Hamilton, the defending world champion, leads the driver standings by five points after three races.
The next scheduled race is the British Grand Prix at Silverstone on 2 August. All races are live on Sky Sports .