Bernie Ecclestone has expressed doubts about how successful F1 will be in the United States, despite the fact that the country is set to have two races on the calendar in the next two years.

Despite question marks about whether it would take place, the race in Austin is due to be held for the first time next season before a race in New Jersey is also added to the schedule the following year.

Next season's race at the Circuit of the Americas will be the first F1 race on US soil since the final race at Indianapolis back in 2007 but despite the fact two races are now planned, Ecclestone said he wasn't sure how quickly the country would embrace the sport.

"We've got a maximum of two races in America and when you consider the country is as big as Europe and we've got several races in Europe, it's difficult," he told Al Jazeera. "If we had a lot more races there and a lot more television it would be okay.

"It's a bit like the rest of America in that they want to see a profit before they start something and it's not easy to do that."