The International Cycling Union received USADA's report last week and has until the end of the month to decide whether to ratify the decision to strip Armstrong of his Tour titles or appeal to the Court of Arbitration for Sport.
"All we can confirm is that the deadline is Oct. 31," UCI spokesman Enrico Carpani told The Associated Press on Thursday. "But it could happen anytime from tomorrow onwards."
USADA banned Armstrong for life and said he should be stripped of his tour titles because of his involvement in "the most sophisticated, professionalized and successful doping program that sport has ever seen."
The USADA report has already cost Armstrong key sponsors, including Nike and Anheuser-Busch. Armstrong also stepped down on Wednesday as chairman of the Livestrong cancer charity he founded.
Former UCI President Hein Verbruggen said he expects the governing body to respond late next week.
"The UCI is studying the USADA report and they will issue a report ... toward the end of next week," Verbruggen told The Associated Press in a telephone interview.
The Dutchman was UCI president from 1991-2005. Armstrong won the Tour de France seven straight times from 1999-2005.
Verbruggen also issued a statement through the UCI on Thursday contesting an article in Dutch newspaper De Telegraaf that said he believed there is no evidence against Armstrong.
"My reaction (to the newspaper) was strictly limited to the fact that Lance Armstrong was never found positive by the anti-doping laboratories, that there was no positive test and that there was nothing to be covered up," Verbruggen said.
The USADA evidence cites several of Armstrong's former teammates who detail entrenched doping among riders on Armstrong's teams during his Tour wins.
Associated Press writer Mike Corder in The Hague, Netherlands, contributed to this report.