Formula 1 has abandoned plans to hold a grand prix in Miami in October 2019 and has instead delayed the race's intended debut until the following year.
A statement from F1 commercial boss Sean Bratches said time had run out "to deliver the best possible wheel-to-wheel racing experience" in 2019.
He said negotiations were "complicated" but that plans for the race had made "significant progress".
The decision to postpone had been made with the Miami authorities, he said.
Bratches said F1 was "committed to expansion in the US and to Miami in particular".
F1 hopes to add races in what they call "landmark cities" on the east and west coast to the current US Grand Prix at the Circuit of the Americas in Austin, Texas, which has been held since 2012.
Bratches added that F1 would hold one of its "fan festivals", where teams run cars around the streets and drivers engage with fans, in Miami in October.
The statement said discussions over the track layout, which is in the downtown and port areas, were central to the delay.
Bratches said that F1 wanted to "deliver the best possible race", adding: "If that meant waiting until 2020, then that was far more preferable than signing off on a sub-optimal race track, just to do a deal."