State funding for the 2012 US grand prix venue in Austin, Texas, is not yet guaranteed.
Autoweek reports that while construction of the bespoke Circuit of the Americas is well advanced, the matter of $30 million in state funding is still unresolved.
Indeed, the report said even Texas' land commissioner and also the attorney general are not sure if the funds will be released after November's inaugural race.
Organiser Steve Sexton said: "We have worked with the local organising committee in following the process to secure and host this international event."
Meanwhile, the president of the 2013 American grand prix in New Jersey, Tom Cotter, is leaving that role at the end of August.
He said in a statement he has "full faith in the grand prix of America team and look forward to sitting in the grandstands at a world-class race in 2013."