Brawn, the new F1 sporting chief, agrees that some of the new races could be in America.
"I think so," he told the Italian newspaper Corriere della Sera.
"But the priority is the quality of the events. North America is important but so is Asia and Europe.
"How many races should we have? We must not inflate the calendar. 20-21 is the maximum. France will be back next year and perhaps Germany as well. And Monza is very important," Brawn added.
As for speculation F1 could rev up the 'show' by bringing back screaming normally-aspirated engines, Brawn insisted: "Unthinkable.
"However, we are thinking about the evolution of the hybrid engine."
Another option to spice up F1 would be to give Pirelli some competition from another tyre maker, but Brawn answered: "Competition is useful, but it's expensive.
"And Pirelli has done a great job -- it's too easy to criticise them. That said, we will analyse which tyres will be most suitable for the F1 we have in mind."