Speaking in Abu Dhabi on Saturday, Formule One supremo Ecclestone suggested there were issues between the parties involved with the Circuit of the Americas venue in Austin, Texas - those developing it and those who own the contract to stage the race.
He said: "Right now I wouldn't want to put my money down it will happen. I hope it will and we are doing our best to make it happen.
"They want it to happen, so they'll sort the thing out. I've said 'You guys have to fall in love. Get married'."
But in a statement published by the Austin Statesman newspaper, circuit president Sexton said: "Our funding is secured and construction is on schedule, so we don't understand Mr Ecclestone's comments.
"He has expressed great interest in the Austin race and in expanding the F1 brand into the United States."
Tavo Hellmund, the man behind the Full Throttle Productions company who are staging the race in November next year, has made it clear Ecclestone does not suffer fools gladly.
"Mr Ecclestone has been incredibly patient with the challenges here in Austin," said Hellmund.
"Full Throttle Productions has worked tirelessly to bring the Formula One United States Grand Prix to Austin.
"It is now the responsibility of the Circuit of the Americas to make this project happen before Mr Ecclestone's patience runs out."