The American, who was stripped of his seven Tour de France titles for doping, plans to go over this year's "Grande Boucle" route one day before the main race with former England footballer Geoff Thomas. The pair say they will raise money for cancer sufferers.
But Armstrong has been widely criticised.
"I think he needs to bear in mind that he may not get quite the welcome he would like in France riding around the route of the Tour the day before," International Cycling Union (UCI) president Brian Cookson told AFP at the SportAccord convention in Sochi, Russia.
The UCI president renewed his call for Armstrong to give up the planned ride. "It is undesirable, I think it is disrespectful. I think there are plenty of ways of raising money for charity that Lance could do."
Armstrong and former footballer Thomas have both battled back from cancer and Thomas invited Armstrong to join him on his "One Day Ahead" ride to raise money for the Cure Leukaemia charity.
