CAPE TOWN, South Africa (AP) — The head of the U.S. Anti-Doping Agency says his message to Lance Armstrong remains the same: Cooperate fully with us if you want to win back some of your reputation.

USADA chief executive Travis Tygart tells The Associated Press it is "premature" to talk about a reduction in Armstrong's life ban from organized sports if he cooperates. But he says the disgraced rider still has a chance to come forward and help himself and the sport.

There has been speculation that Armstrong may seek to lessen his sanction in return for helping USADA's ongoing investigation into doping in cycling.

But Tygart says Armstrong has to "come in" and be "truthful on all fronts" — something he says the American hasn't done yet.

Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.