Liberty Media looks set to push ahead with plans for greater than 21-race calendars in the future.
Vietnam and Zandvoort are joining the 2020 schedule, but Liberty has decided to keep the 21-race limit for now by ousting two existing promoters.
However, F1 CEO Chase Carey seems determined to follow through with an earlier plan to expand the calendar to up to 25 races per season.
"We have agreements with Vietnam and Zandvoort for the 2020 calendar, which will be finalised in the coming weeks," he told the Austrian broadcaster Servus TV.
"For us, it's about quality over quantity. But we have talked about another race in the US and we would like to return to Africa," Carey added.
"There are 21 races now, but if we find the right places, then it makes sense to add a few more."
