Amid the circuit's financial troubles, F1 chief executive was quoted on Sunday in the German press: "We do not accept it (the Nurburgring's proposal) as financially feasible and therefore end the negotiations".
But Nurburgring Automotive GmbH chief Jorg Lindner is not giving up.
He told the Rhein Zeitung newspaper on Tuesday: "We have the exclusive rights to Formula One at the Nurburgring, and we insist on it."
Ecclestone said on Tuesday: "I am doing my best to make sure we have an event in Germany.
"At the moment I can't say whether it will be Hockenheim or Nurburgring," he told the Associated Press.