Zandvoort must secure major backing by the end of March if it is to bring the Dutch Grand Prix back to the Formula One calendar next year, the Netherlands Sports Council said on Monday.
The NLsportraad said in an open letter that Zandvoort had failed to secure financial support from central government after signing a letter of intent with Formula One Management (FOM) in December.
The government has said it would be willing to facilitate but not subsidise any race.
"Circuit Zandvoort is [currently] trying its best to find large sponsor partners to complete their business case.