Norway, Sweden and Finland had asked Tour de Ski organisers to shorten the programme due to their concerns. 

Norwegian cross-country star Therese Johaug said she would only compete if there was a maximum of five races. 

International Ski Federation (FIS) cross-country race director Pierre Mignerey rejected this idea, however, claiming it was not "realistic". 

Norway have now withdrawn from the competition, as reported by NRK.

"The health of the athletes and the support staff is a priority for us," said Espen Bjerwig, Norwegian cross-country skiing team manager. 

Norway is one of the leading nations in the cross-country discipline, with successful athletes such as Olympic and world champion Johannes Høsflot Klæbo and Johaug now set to miss out on the Tour de Ski.

Eight Tour de Ski stages are currently scheduled for January 1 to 10. 

Val Müstair in Switzerland is to host three races, with Toblach in Italy then staging two.

Competition is set to conclude in Italy with three races in Val di Fiemme.  

Along with Sweden and Finland, Norway has already withdrawn from this month's FIS Cross-Country World Cup events over coronavirus fears. 

The FIS is still planning to host competition in Davos on Saturday and Sunday (December 12 and 13) and Dresden on December 19 and 20, despite these withdrawals. 

The Norwegian Ski Association cited the 2021 FIS Nordic World Ski Championships, due to begin in Oberstdorf in late February, as its priority for the season when announcing it was opting out of this month's World Cups.

The team's experience at Ruka in Finland in November, when the World Cup season began, was also mentioned.

Athletes and officials claimed maintaining social distancing was more demanding than they had anticipated.