Organisers of a planned US Grand Prix in Austin, Texas, have told Formula One supremo Bernie Ecclestone that they will pay a sanctioning fee for 2012's race if he revises an "unrealistic and unfeasible" contract.
The 81-year-old Briton responded on Thursday by casting further doubt on the event going ahead.
Ecclestone has already made clear that he has lost patience and last week gave the city's Circuit of the Americas a deadline of this weekend's Brazilian Grand Prix to pay the required fees and sign a contract.
"We have been ready to send Mr Ecclestone a sanctioning fee check for some time now," said Bobby Epstein, founding partner of Circuit of The Americas, in a statement.
"He hasn't received it yet because the new contract presented to us two weeks ago contained unrealistic and unfeasible demands.
"We have signed and returned a contract similar to what we anticipated receiving. This race should be a reality, but if we are going to make the 2012 race date, we must receive a counter-signature in the coming few days."
Asked by Reuters at the Interlagos circuit whether he thought the Texas race might now happen, Ecclestone was dismissive.
"I doubt it," he said, with a copy of the Austin statement in his hands.
"The truth is they're not complying with the terms and conditions of the contract. And as we make the contract, we will award the event or not award the event. They are not awarding anything to us.
"It's normal," he added.
"They have been messing around now for four months, there's two partners arguing and two different groups arguing with each other and in the end none of them have got the money."
Asked whether his contract was really "unrealistic and unfeasible", Ecclestone replied: "Yeah, well they shouldn't sign it. My advice to them is don't sign it. And they probably won't get the opportunity."
The race would have marked a return to the United States for Formula One, which last staged a race at Indianapolis in 2007.
Since Austin was announced, Ecclestone has also done a deal for a race in New Jersey against a backdrop of the Manhattan skyline for 2013.
Construction was halted at the Austin circuit this month while the Texas Comptroller of Public Accounts has ruled out the state paying any public funds in advance of the race being held.