Salvini said in a statement it was "imperative to concentrate all efforts on coping with the emergency," including avoiding a traffic overload in the area, which has been battered by bad weather in recent days.
The Grand Prix, a home race for Ferrari, is scheduled to be the sixth round of the season and first of a triple header with Monaco and Spain following on successive weekends.
Red Bull have won every race so far and double world champion Max Verstappen is 14 points clear of team-mate Sergio Perez.
The paddock remained closed on Wednesday, with Formula 1 personnel asked to leave the circuit on Tuesday amid fears of flooding as water levels rose in the Santerno river that runs alongside the track.
An update on the situation is expected later on Wednesday.
Cars are not due to be on track until Friday but the advance team and technical personnel had arrived to set up the garages and hospitality.
Italy's civil protection agency on Monday issued a red alert weather warning for the northern region.
