AUSTIN, Texas — Taking Lance Armstrong’s refusal to fight as an admission of guilt, the U.S. Anti-Doping Agency announced Friday that it would strip the retired cyclist of all seven of his Tour de France titles.

The move was expected after Armstrong announced late Thursday that he would not participate in an arbitration process.

“Nobody wins when an athlete decides to cheat with dangerous performance enhancing drugs, but clean athletes at every level expect those of us here on their behalf to pursue the truth to ensure the win-at-all-cost culture does not permanently overtake fair, honest competition,” USADA CEO Travis T. Tygart said. “Any time we have overwhelming proof of doping, our mandate is to initiate the case through the process and see it to conclusion, as was done in this case.”

“As is every athlete’s right, if Mr. Armstrong would have contested the USADA charges, all of the evidence would have been presented in an open legal proceeding for him to challenge,” the USADA said in a statement. He chose not to do this knowing these sanctions would immediately be put into place.”

The Tour de France issued a statement saying it would continue to monitor the case. This is new territory for doping matters. The Tour has stripped two cyclists of their wins. But both cyclists — Floyd Landis in 2006 and Alberto Contador in 2010 — tested positive for a banned substance while actually competing in the race.

Armstrong won his titles from 1999-2005 and last competed at the Tour in 2010.

USADA never detailed its charges in a letter it sent to Armstrong in June. In the statement it released Friday, USADA stated “numerous witnesses provided evidence to USADA based on personal knowledge acquired, either through direct observation of doping activity by Armstrong, or through Armstrong’s admissions of doping to them that Armstrong used EPO, blood transfusions, testosterone and cortisone during the period from before 1998 through 2005, and that he had previously used EPO, testosterone and HGH through 1996.”

The agency said, “Witnesses also provided evidence that Lance Armstrong gave to them, encouraged them to use and administered doping products or methods, including EPO, blood transfusions, testosterone and cortisone during the period from 1999 through 2005. Additionally, scientific data showed Mr. Armstrong’s use of blood manipulation including EPO or blood transfusions during Mr. Armstrong’s comeback to cycling in the 2009 Tour de France.”

On Thursday, Tim Herman, Armstrong’s Austin-based attorney, sent a letter to USADA’s general counsel William Bock, informing the quasi-governmental agency that it should not be allowed to retroactively punish the retired cyclist because it is not their jurisdiction.

“You are on notice that if USADA makes any public statement claiming, without jurisdiction, to sanction Mr. Armstrong, or to falsely characterize Mr. Armstrong’s reasons for not requesting an arbitration as anything other than a recognition of (International Cycling Union) jurisdiction and authority, USADA and anyone involved in the making of the statement will be liable,” Herman said in the letter, which was provided to the Austin American-Statesman.

Armstrong, who insisted he is innocent of all charges, had until midnight Thursday to tell USADA whether he planned to choose arbitration and fight doping charges the agency brought against him. USADA has a 58-2 record when athletes fight charges, although the Armstrong case is unique because there are no positive tests for performance enhancing drugs, although the cyclist estimates he provided more than 500 samples throughout his career.

Armstrong said Thursday, “USADA cannot assert control of a professional international sport and attempt to strip my seven Tour de France titles.

“I know who won those seven Tours, my teammates know who won those seven Tours, and everyone I competed against knows who won those seven Tours.

“We all raced together. For three weeks over the same roads, the same mountains, and against all the weather and elements that we had to confront. There were no shortcuts, there was no special treatment. The same courses, the same rules. The toughest event in the world where the strongest man wins. Nobody can ever change that. Especially not Travis Tygart.”

The Tour has taken away titles from two riders: Floyd Landis in 2006 and Alberto Contador in 2010. Each tested positive for a banned substance while riding to his Tour victory.

If Armstrong’s titles are taken away it is unclear who would be declared the winner. Most of the cyclists behind Armstrong on the podium were suspended for using drugs including Jan Ullrich, Ivan Basso and Alexander Vinokourov.

Shortly after Armstrong made his decision public Thursday, statements of support were issued by the founding chairman of the Lance Armstrong Foundation, the CEO of the American Cancer Society and the president of the Campaign for Tobacco-Free Kids.

Nike has also extended its support to Armstrong.

In June, USADA charged Armstrong and five others with being involved in what the agency described as a doping conspiracy dating to the 1990s. USADA, in recommending a lifetime ban for Armstrong and the stripping of all Tour titles won from 1999 to 2005, never revealed specifics on why the agency was recommending the charges. The agency, which is partially funded by Congress, said it had eyewitness testimony from at least 10 unnamed former associates of Armstrong who would testify to his drug use.

Armstrong asked for a permanent injunction in federal court to halt USADA’s plans, saying the agency did not have jurisdiction and that it was violating his constitutional rights to due process. U.S. District Judge Sam Sparks dismissed the case earlier this week, although he said USADA’s charging document was of “serious constitutional concern.”

Allegations of doping have dogged Armstrong since he won his first Tour. He was cleared by the French government in 2002 and an independent investigator in 2006. A two-year federal investigation into doping and possible fraud was finished in February, with the government declining to bring charges.