Organisers have said that they are "hopeful" Austin will continue to host the United States Grand Prix, despite the race budget being reduced.

Since 2012, the state of Texas had been adding $25m (£16.5m) a year to costs for the race, but this season, the contributions were cut by 20%.

There are now concerns that the grand prix will be taken off the calendar, but organisers at Circuit of the Americas, where Lewis Hamilton won his third world title last month, remain optimistic that Austin will continue to host the race.

"The grand prix has generated hundreds of millions of dollars in positive economic impact," BBC Sport quotes organisers as saying. "We're hopeful Formula 1 will continue to race here.

"The grand prix is a cornerstone event that brings global exposure to Austin and makes the circuit a year-round destination for sports and entertainment."

Meanwhile, the drivers are preparing for the penultimate race of the campaign in Brazil this weekend.