US grand prix organisers say they would welcome more American races.
F1’s new owners, the US media group Liberty Media, are keen to expand the calendar to up to 25 races, with potential events in US cities like Los Angeles, Las Vegas or New York.
Bobby Epstein, boss of the only US race at present in Austin, Texas, said he would welcome that.
"In the long run, it will bring more attention to the sport and our race," he told the Austin American Statesman newspaper.
"One of the drawbacks of F1 in America is most races start at 7am or even earlier. If you add a race in our time zone, it will grow the fan base, and that’s good for all of us," he added.
However, Epstein expressed concern that the new US races would likely take place on street circuits.
"Street races tend to be very boring," he said. "There’s not much opportunity to overtake. A fan can’t watch many turns."