Lance Armstrong has admitted to "difficult" times since a report accused the shamed cyclist of being at the heart of the most sophisticated doping programme ever seen in sport. Making his first public remarks since the release of United States Anti-Doping Agency's damning report, Armstrong did not refer directly to the scandal, saying: "It's been a difficult couple of weeks for me and my family, my friends and this foundation. We will not be deterred. We will move forward." The 41-year-old American made his comments to 1,500 guests at a gala fundraiser for cancer charity Livestrong, which he founded 15 years ago after fighting testicular cancer. On Wednesday he stepped down as its chairman to protect the foundation from the scandal. That was the same day corporate sponsors, including sportswear giant Nike, dropped him in the uproar over the Usada report, which cites more than two dozen witnesses including some former teammates and accuses Armstrong of being at the heart of sport's "most sophisticated, professionalised and successful doping programme". World cycling's governing body the International Cycling Union (UCI) will respond to the report tomorrow, announcing whether it backs Usada's demand that Armstrong be banned for life and stripped of the seven Tour de France titles that made him a sports icon. UCI president Pat McQuaid will also come under scrutiny for his handling of doping issues. Anne Gripper, who ran UCI's anti-doping arm from 2006 to 2010, told Australia's The Age newspaper that the UCI should have handled things better. The Usada report, Gripper said, showed "not so much that he [Armstrong] was a doping cheat - I think everybody accepts that just about all cyclists were doing it - but the way he orchestrated that programme and, more importantly, the bullying and the tactics used to influence the behaviour and choices of young impressionable riders". Gripper also accused Armstrong of telling "the sport how to administer its rules", in reference to the UCI waiving a 13-day window to allow the Texan to race the 2009 Tour Down Under. "I have always said Armstrong's influence was a danger in the sport," Gripper told The Age . "He was allowed to ride in the 2009 Tour Down Under. He shouldn't have been. Once again, for Lance, special consideration was provided. "The UCI may have failed to take some actions that we should have taken at the time but, since 2006, we have been really committed to this issue." Asked if she felt McQuaid faced a limited future at the UCI, Gripper said: "I don't know - his commitment to this was very strong while I was there. It may have wavered a bit."