There will be no German grand prix at Hockenheim in 2019.
The circuit is hosting a race next month, but organisers have been unable to reach a new deal with Formula 1 owner Liberty Media.
"We are not surprised but of course it's a great pity. We talked with Liberty Media but made it clear time and time again that we are interested in continuing only if the financial risk is minimised.
Seiler said Hockenheim is now hoping for a comeback in 2020.
"The goal remains a fundamentally changed business model. To what extent our ideas can be aligned with those of F1 in the future, we will see," he said.
As for next month's German grand prix, Seiler said Hockenheim is hoping to attract a crowd of 70 000 on Sunday, which would mean financially breaking even.
It is possible that Liberty Media will now pursue its talks with the Nurburgring.
"Since the beginning of 2017, we have had proactive negotiations with Liberty Media and, in March 2018, we discussed new opportunities for cooperation.
Our proposals are on the table, now it's up to Liberty Media to decide," said chief executive Mirco Markfort.
