France anti-doping agency president Pierre Bordry announced his resignation Friday after a five-year tenure in which he regularly clashed with Lance Armstrong and cycling officials.

Bordry said that he will step down as soon as his successor is appointed, probably next month.

Bordry said he was happy to leave with "a very good record" in the fight against doping, but added the French agency should obtain "perennial resources" to improve its work.

"The agency structured and organized itself during this five-year spell," Bordry told the AP in a phone interview. "And I'm glad that the World Anti-Doping Agency says in its statistics that the AFLD is the most efficient agency in the world."

Bordry refused to give any reason for his resignation, but he battled last year with French authorities to obtain a proper budget for the agency.

The 71-year-old Bordry always has had a tense relationship with Armstrong. Bordry promised last week to collaborate fully with a U.S. federal investigation into organized doping in professional cycling, including Armstrong.

The seven-time Tour de France winner reacted to Bordry's resignation with a short message on Twitter: "Au revoir Pierre."

Bordry said he will hand over Armstrong's "B" samples from the 1999 Tour to Jeff Novitzky if the U.S. Food and Drug Administration agent makes an official request.

French sports daily L'Equipe reported in 2005 that Armstrong's backup samples from 1999 contained EPO -- a banned blood-boosting hormone. Armstrong was cleared by an independent panel.

Before last year's Tour de France, the AFLD said Armstrong did not fully cooperate with one of its testers who showed up at his home in France to collect blood, urine and hair samples.

The agency said Armstrong was out of line and warned it could prevent him from racing in the Tour. He eventually competed in the race.

Bordry also was at odds with the International Cycling Union and harshly criticized the UCI's biological passport this year, questioning the program's reliability and suggesting the UCI was misusing its information.

"Our agency is known worldwide," Bordry said. "We showed to all IOC members that doping is not unavoidable, provided that one really wants to fight it."

Bordry gained major attention in 2008 when the AFLD was in charge of the drug testing during the Tour de France following a feud between the race organizers and the UCI. Bordry decided that year that riders would not be just randomly tested, but also picked by the AFLD.