Formula One boss Bernie Ecclestone gave the organizers of the US Grand Prix until the end of next week to sign a contract or next year's race at Austin, Texas will be called off.
Ecclestone wants the dispute with Circuit of the Americas officials in Austin settled before the season-ending Brazilian Grand Prix on November 27.
"It's all very simple - they don't have the money," Ecclestone told The Associated Press on Thursday.
"We don't have a contract. If they want to come back to us, if it's not signed before the end of next week, I suppose it won't be on the calendar next year."
Ecclestone wants a guarantee or a letter of credit that he will be paid.
"We have been working on this now for quite a few months and years so we can't do any more," Ecclestone said.
"We have a World Motor Sport Council meeting on the 7th of December and we need to prepare everything before that."
The dispute has been caused by F1's decision to scrap a previous contract it had with Tavo Hellmund, a former race driver with long family ties to Ecclestone, who was originally granted the right to stage the US Grand Prix.
The deal with Hellmund was recently canceled over a contract breach, and F1 officials have instead been negotiating with the track developers, Circuit of the Americas.
Ecclestone said it was likely there would be one fewer race in the 2012 season if the Texas organizers do not sign the contract in time.
Ecclestone said he had not considered bringing forward the grand prix in New Jersey which is due to take place from 2013.
A 10-year agreement has been agreed on to hold the race along the Hudson River waterfront, providing striking views of the Manhattan skyline.
