The Circuit of the Americas has agreed to pay the sanctioning fee for the 2012 US Grand Prix, but has revealed that it is not willing to agree to all of Bernie Ecclestone's demands.

Serious doubts were cast over the US Grand Prix last week when it emerged that the circuit did not have a valid contract with Formula One Management to hold the race. Last Friday Ecclestone said the circuit had a week to agree to a new contract, adding "if they had the money, I'm sure there would be no problem."

In a statement on Thursday the Circuit of the Americas said it is now ready to pay up front for the 2012 race and has proposed an advance payment schedule for the following years.

"Circuit of The Americas has responded to Formula One Management's contract requirements by agreeing to an immediate cash payment of the sanctioning fee for the 2012 United States Grand Prix (US GP)," read the statement. "In addition, Circuit of The Americas has offered to establish an advance payment schedule for US GP races beyond 2012. The offer comes after several weeks of talks, and once accepted, will secure the US GP on the Formula One race calendar."

However, Circuit of the America's investor Bobby Epstein said there were some parts of the contract he could not agree to and has only signed up to the terms he was expecting to agree to.

"We have been ready to send Mr. Ecclestone a sanctioning fee check for some time now," Epstein said. "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 countersignature in the coming few days. We believe the teams, fans, sponsors and local business share our enthusiasm and hope that their voices will be heard."

Asked about the chances of a US Grand Prix in the Interlagos paddock, Ecclestone, who was shown the statement, said: "I doubt it. 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. 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."

When it was put to Ecclestone that the circuit had said his terms were unrealistic and unfeasible, the F1 supremo responded: "Yeah, well they shouldn't sign it. My advice to them is don't sign it. And they probably won't get the opportunity."