Sporting events in the Netherlands will have to take place without fans until there is a coronavirus vaccine, Dutch Health Minister Hugo de Jonge says.
Prime Minister Mark Rutte said on Wednesday that organised sport could resume from 1 September.
But De Jonge said mass gatherings would be barred until a vaccine is developed.
"We cannot yet mention a date for the last step, the mass gatherings," he wrote in a letter to the Dutch parliament.
"That is actually only possible if there is a vaccine and no one knows how long it will take.
"We hope of course soon, but a year or more is very real."
Covid-19 has infected more than 41,000 people in the Netherlands and caused 5,288 deaths.
The top two Dutch football leagues were abandoned last month with no promotion or relegation and no champions.