As Liberty Media puts together the 2020 calendar, strong doubts about the fate of three existing races remain.

The F1 owner has inked new deals with Zandvoort and Vietnam, with chief executive Chase Carey saying the calendar will remain static at 21 races by dropping two current grands prix.

The most endangered are Barcelona and Hockenheim.

"Am I worried? Yes, I'm worried because I don't like losing my home grand prix," said Spaniard Carlos Sainz in Paul Ricard.

And German driver Nico Hulkenberg said of Hockenheim: "It would be sad to see it go but like Carlos said, it's not down to us."

Also in serious doubt is Sergio Perez's home race, in Mexico City.

"I am trying to support the organisers but I haven't heard anything," the Racing Point driver said.

"Negotiations continue and (promoter) Alejandro Soberon and his team are doing everything possible to keep the race, but not everything depends on him.

"I hope for the best. I think we will find out some news in the near future," added Perez.

Also without firm contracts for 2020 are Silverstone and Monza, although it is believed those races are basically safe.