The 2016 United States Grand Prix remains in doubt after the FIA confirmed the race's presence on the Formula One calendar is subject to agreement with the promoter.
Lewis Hamilton won the 2015 world championship with victory in October's race at the Circuit of the Americas in a grand prix heavily disrupted by wet weather.
Officials for the circuit in Austin, Texas say the inclement weather that saw much of the race weekend cancelled has left them struggling financially.
A decision by the Texas governor's office to slash public funding for the track by nearly 20 per cent has not helped matters.
Yet the race is still scheduled to be held on October 23, 2016, although it has been listed on the calendar with an asterisk.
A new race in Baku, Azerbaijan is to be held on June 19 while the German Grand Prix is back after being dropped for the 2015 campaign following a failure to agree on a venue.
The 21-race calendar will make the 2016 season the longest in F1 history.
Additionally, the FIA has introduced a number of regulation changes for the new campaign.
Teams will be allowed three dry-weather compounds in each round instead of two while the number of power unit tokens allowed for in-season development has been revised to 32.
Furthermore, the padded areas around the driver's head will be increased in thickness to improve safety.