2020 Formula 1 season begins with Australian Grand Prix on 15 March

Mercedes' Valtteri Bottas won 2019's season-opening Australian Grand Prix ahead of team-mate Lewis Hamilton and Red Bull's Max Verstappen

The 2020 Formula 1 season will start on 15 March with the Australian Grand Prix in Melbourne.

The 25th race in Melbourne, which first hosted the sport in 1996, will mark the start of F1's 70th anniversary year.

F1 chairman Chase Carey said: "The Albert Park circuit is one of the most popular on the calendar. There is no better place to start the 2020 season."

The date, the same weekend as the start of last season, was announced without any further details of the calendar.

F1 has already said there will be two new races on the schedule next year, with the return of the Dutch Grand Prix in Zandvoort and a new race in the Vietnamese capital Hanoi.

But four races are in doubt, with Britain, Germany, Mexico and Spain all out of contract at the end of this season.

At least two of those races are expected to lose their places on the calendar, keeping the total number of races next year at 21.

Spain and Germany are considered most vulnerable, and the Mexican government has expressed reservations about continuing with the race, but there are also doubts about the British event.

F1 and Silverstone had been close to agreeing a new contract but the track's owners, the British Racing Drivers' Club, are holding off on signing it after F1 admitted it wanted to hold a race in London.

Italy's contract also ends this year, but F1 announced in April that it had reached an "agreement in principle" for a new deal through 2024. That contract has not yet been confirmed.

There is also confusion surrounding the future of the Brazilian Grand Prix.

The country's President Jair Bolsonaro has said the race will move to a new track in Rio de Janeiro from next year.

But Sao Paulo's Interlagos circuit still has a year left on its contract, and there is widespread scepticism within F1 about the event in Rio. Several sources have told BBC Sport that "it's not going to happen".