Oprah Winfrey has said Lance Armstrong "did not come clean in the manner I expected" during a two-and-a-half hour interview with the disgraced cyclist.
The shamed sportsman reportedly admitted using performance-enhancing drugs to the US talk show host, ending a decade of denial.
Armstrong was stripped of his seven Tour de France titles last year after a US Anti-Doping Agency (USADA) report said he was a ruthless competitor, willing to go to any lengths to win the prestigious race.
Speaking to CBS after the interview, Winfrey said she was "satisfied" with Armstrong's confessional.
"I would say he did not come clean in the manner that I expected," she said.
"It was surprising to me. I would say for myself, my team ... we were mesmerised and riveted by some of his answers.
"I feel he answered the questions in a way that (suggested) he was ready. I can only say I was satisfied with the answers."
Asked if Armstrong was contrite during the interview, Winfrey said: "I choose not to characterise.
"I would rather people make their own decisions about whether he was contrite or not. I felt that he was thoughtful, I thought that he was serious, I thought that he certainly had prepared himself for this moment. I would say that he met the moment.
"At the end of it... we were both pretty exhausted."
She also dismissed fears expressed before the interview that she may give Armstrong an "easy ride" adding that the confessional would be screened over two shows, to avoid cutting it down too much.
Winfrey said she had not planned to comment on the interview before it was screened, but decided to do so after it was widely reported that he had admitted drug use.
The interview with Winfrey comes as a member of the International Olympic Committee (IOC) claimed cycling could be dropped from the Olympics if Armstrong implicates the sport's governing body in covering up a widespread doping scheme.
IOC member Dick Pound said the committee might be left with no choice other than to take drastic action if Armstrong proved the International Cycling Union (UCI) acted improperly.
"The only way it is going to clean up is if all these people say 'hey, we're no longer in the Olympics and that's where we want to be so let's earn our way back into it'," Mr Pound said.
Sky News sports editor Nick Powell said Mr Pound had waged a campaign against the UCI for a long time.
Powell doubted cycling would be banned from the Olympics because of Armstrong's case.
"It's not going to happen. To ban lots and lots of clean cyclists because of one man ... would be absurd," he said.
"What it does do is indicate the level of feeling and the kind of things we're going to get more of once we hear what Lance Armstrong's actually got to say."
The UCI has urged Armstrong to testify before its independent commission on doping.
"If these reports are true, we would strongly urge Lance Armstrong to testify to the Independent Commission established to investigate the allegations made against the UCI in the recent USADA reasoned decision on Lance Armstrong and the United States Postal Service (USPS) team," the federation said.
USADA chief executive Travis Tygart labelled the doping regime allegedly carried out by the US Postal Service team that Armstrong once led "the most sophisticated, professionalised and successful doping programme that sport has ever seen".
The interview with Winfrey is Armstrong's first public response to the report.
He is not expected to have provided a detailed account about his involvement, or addressed in depth many of the specific allegations made in the more than 1,000-page report.
A government source has told ABC News that Armstrong had also met officials to discuss paying back some of his former team's sponsorship money from the US Postal Service.
The source also suggests Armstrong may give the names of others involved in illegal doping - leading to a possible reduction of his lifetime ban.
The American apologised to staff at his Livestrong Foundation , saying he was sorry for the distress he had caused. He vowed he would repair the foundation's reputation.
Armstrong is said to be worth around $100m (£62m). However, most sponsors dropped him after USADA's scathing report - at the cost of tens of millions of dollars - and soon after, he left the board of Livestrong.