The Vietnam Tourist Board appears to put next month's Grand Prix in Hanoi in doubt, especially for Ferrari, AlphaTauri and Ferrari customer teams Alfa Romeo and Haas.
The Vietnam Tourist Board today states that: "All travellers entering Vietnam from China, South Korea, Italy, and Iran must carry out medical declarations and 14-day medical quarantine before entering the country."
While Pirelli's tyres are manufactured in Romania and Turkey, many members of the Milan-based company's F1 personnel are based in Italy.
Ferrari's Mattia Binotto has revealed that his team sought FOM's "assurance before leaving".
"I don't think we can discover when teams arrive what can be or what will be the situation," he said. "So if there are any medical screenings, we need to know about them. You need to know exactly what's about. We need to understand what the consequences are in case of any problem."
If Ferrari and AlphaTauri are unable to contest the Vietnam race, it could still go ahead as company documents state that F1 "must attempt to procure that at least 16 cars participate in the World Championship".