Attorney Timothy Herman sent a letter to the U.S Anti-Doping Agency this week stating Armstrong would be unable to accept an invitation to discuss the matter but was inclined to cooperate with the International Cycling Union (UCI) in its "truth and reconciliation" inquiry into the doping scandal that included Armstrong being stripped of his seven Tour d' France victories.
Herman explained the U.S. agency was focused solely on the U.S. Postal Service team Armstrong once led, while the UCI was interested in doping throughout the professional cycling world, CNN said.
Herman also said Armstrong's schedule made him unable to meet with the American agency for at least two weeks.
A spokesman for the USADA told CNN Armstrong had plenty of advance notice about their invitation, and the investigation would move forward regardless.