The Vietnam GP will not feature on the 2021 Formula 1 calendar.
Vietnam had been due to make its debut on this year's F1 calendar in April at a new street track in Hanoi before it was cancelled due to the coronavirus pandemic.
But the decision to drop it for 2021 is understood to be linked to political issues in the country.
When the provisional schedule was revealed by F1 later on Tuesday, Vietnam's planned April slot was left vacant.
Meanwhile, Brazil's Interlagos is set to continue for next season with work on a planned new circuit in Rio still awaiting government approval to start work.
An F1 spokesperson said: "Our calendar will be announced tomorrow [Tuesday] and we are not going to give a running commentary before its publication.
"It also needs to go to the World Motor Sport Council for approval."
As reported last month, the season is planned to open in Australia in its usual mid-March slot as part of what F1 chairman Chase Carey has described as a planned schedule that is "closer to normal" after the Covid-19 affected cancellations of this year.
F1 has mostly raced in Europe since the season belatedly began in July, with a 17-race campaign including some venues not on the original 22-race 2020 schedule.
The first 10 races of this year were called off due to the pandemic, with only nine events of the original calendar rescheduled.
Saudi Arabia will stage its first Grand Prix next season on a street circuit in Jeddah, with the night-time event set to be the penultimate round of the season ahead of the usual Abu Dhabi closer.