Formula One is working with teams to identify U.S. drivers who might make it to grand prix racing but no Americans are likely to come through in the near term, chief executive Stefano Domenicali said on Friday.
The most recent was Alexander Rossi, who started five races with a highest placing of 12th for the now-defunct Marussia team in 2015 before leaving to go on and win the Indianapolis 500 as a rookie in 2016.
"We are working with teams to try to understand what is really the possibility for American drivers to come to the attention of Formula One teams in the short term," Domenicali told analysts on a first-quarter earnings call.
"I don't see that, being very pragmatic and realistic, coming in the next two or three years but maybe after."
Liberty Media-owned Formula One sees the United States as a major market for growth and is adding a second race next year in Miami, along with the existing grand prix in Austin, Texas.
"I know there are teams watching the good drivers that, if they are ready, would be a big boost for the American fans," Domenicali said.
"The people want to see these guys. Therefore the hope that we have is that very, very soon we have American drivers competing against all the others in the Formula One championship."
Haas and Williams both have U.S. owners while U.S.-based investment group MSP Sports Capital have a significant minority stake in McLaren.
There are currently four American drivers in F1's junior feeder series, Formula Three, and McLaren recently signed 13-year-old American go-karter, Ugo Ugochukwu, to a development contract.
Two Americans have won the Formula One world championship since the first in 1950 -- Phil Hill in 1961 and Mario Andretti in 1978.
Mercedes' seven-times world champion Lewis Hamilton spends plenty of time in the United States while Netflix has brought the sport to new audiences with its "Drive to Survive" documentary series.