Lance Armstrong "did not come clean in the way I expected" on whether he used performance-enhancing drugs in his cycling career, talk show host Oprah Winfrey has said in advance of the much-awaited telecast of her interview with the disgraced cyclist.
She told CBS This Morning on Tuesday that her OWN cable network will telecast the two-and-a-half-hour interview unedited over two nights from Thursday.
Originally, a shorter broadcast was planned for one night only.
Winfrey stopped short of confirming a confession and said she would leave to others to decide if Armstrong had been contrite in the interview.
"I didn't get all the questions asked, but I think the most important questions and the answers that people around the world have been waiting to hear were answered," she said.
"I can only say I was satisfied by the answers."
The interview is Armstrong's first since he was stripped of his record seven Tour de France titles after the US Anti-Doping Agency, in a 1,000-page report, put him at the heart of the greatest doping scandal in the annals of cycling.
For a decade he had vigorously denied using banned substances to win his way into the history books.
'Biggest interview ever'
Prior to sitting down with Winfrey in a hotel suite in his hometown of Austin, Texas on Monday, Armstrong, went to the offices of Livestrong, the cancer charity he founded in 1997, and apologised in person to its staff.
"Lance came to the Livestrong Foundation's headquarters [and] offered a sincere and heartfelt apology for the stress they've endured because of him," Rae Bazzarre, Livestrong spokeswoman, told AFP news agency.
Speaking from Chicago, Winfrey - when asked if Armstrong had "come clean" to her - said Armstrong had agreed at the outset not to talk about the content of the interview prior to broadcast.
The New York Times and USA Today newspapers, however, both cited sources with knowledge of the interview saying that the 41-year-old Texan would admit to Winfrey using banned substances in his career.
Cycling commentator Anthony McCrossan says Armstrong's revelations are likely 'fireworks'
"And then, by the time I left Austin and landed in Chicago, you [the news media] all had already confirmed it," she told CBS.
Winfrey, 58, said she went into "the biggest interview I've ever done" with 112 questions, and grilled him so intensely that, during a break at the 100-minute mark, Armstrong asked if their conversation might lighten up.
"It was surprising to me. I would say that for myself, my team, all of us in the room, we were mesmerised and riveted by some of his answers," she said.
In Lausanne, Switzerland, cycling's world governing body, the International Cycling Union, called for Armstrong to give evidence to its ongoing investigation into widespread doping in the wake of his Winfrey interview.
Elsewhere, the South Australian state government said it would be "more than happy" for Armstrong to repay his appearance money from the Tour Down Under event, but it had no legal power to make him do so.