Winfrey discussed the "no-holds barred" interview on "CBS This Morning" Tuesday.
The interview, conducted in Austin, Texas, Monday, was set for broadcast on Winfrey's network Thursday. After the interview, Winfrey tweeted, "Just wrapped with @lancearmstrong More than 2 1/2 hours . He came READY!"
It was a pivot for Armstrong following years of public statements, interviews and court battles in which the former Tour de France winner denied doping and zealously protected his reputation.
Hours earlier, Armstrong appeared at Livestrong, the cancer charity he founded, and apologized.
The cyclist lost all seven of his Tour de France titles following a U.S. Anti-Doping Agency report that portrayed him as a ruthless competitor, willing to go to any lengths to win the prestigious race.
In a recent interview USADA chief executive Travis Tygart described Armstrong and his team of doctors, coaches and riders as similar to a "mafia" that kept their secret for years and intimidated riders into silently following their illegal methods.
Reports: SC orders arrest of Pakistani PM
ISLAMABAD, Jan. 15 (UPI) -- The Pakistani Supreme Court Tuesday ordered the arrest of Prime Minister Raja Pervez Ashraf and 15 others in an alleged kickback case.
The news of the arrest came as Islamabad was in the midst of a huge anti-corruption political rally led by a Pakistani-Canadian Islamic cleric Tahirul Qadri, raising concerns about political stability in the country, CNN reported. Elections are scheduled after March when the current term of the civilian government of Ashraf and President Asif Ali Zardari ends.
The latest developments also come at a time when Pakistan is facing an unending wave of deadly sectarian, separatist, political and militant violence in its major cities, threatening its fragile democracy after decades of military rule.
CNN and local television channels reported the Supreme Court order resulted from allegations of kickbacks going back to when Ashraf had been water and power minister.
The Zardari government and the Supreme Court have not seen eye to eye in recent months in other cases related to graft. Ashraf became prime minister last year after the Court dismissed his predecessor, Yousaf Raza Gilani, following reopening of old graft cases against Zardari.
Qadri had set a Tuesday morning deadline for the Zardari government to resign and caretaker government put in its place. Tens of thousands of people participated in his march to Islamabad from Lahore.
At least 50 dead as Syria shells cities
DAMASCUS, Syria, Jan. 15 (UPI) -- At least 50 people were killed across Syria Tuesday as regime forces shelled major cities and government warplanes assaulted the nation's capital, rebels said.
The rebel Local Coordination Committees of Syria said at least 15 people, including eight children, were killed in Houla by regime shelling, CNN reported.
Tanks were shown on video shelling a highway near the town.
In a video posted on YouTube, a body was seen being pulled from rubble in Aleppo. Three people in Aleppo were reported wounded in a residential area of Aleppo by shelling from a warplane.
Government forces shelled the city of Homs three times, rebels said, killing and injuring dozens of people.
Separately, two Syrian generals captured by rebels pleaded with President Bashar Assad to free them in exchange for "50 innocent civilians."
They said they were being treated well by members of the rebel Free Syrian Army, but that they had not yet received any response from Assad.
In a letter to the U.N. Security Council, the French foreign minister called for aggressive action against Assad and urged the International Criminal Court to try him as a war criminal.
Egyptian court clears 14 in protest deaths
BENI SUEF, Egypt, Jan. 15 (UPI) -- An Egyptian court has acquitted a former security chief and 13 others for the deaths of protesters on the day known as the "Friday of Anger" in January 20ll.
The court found former Beni Suef Security Chief Major General Ahmed Shawky innocent along with a security employee, department head and 11 soldiers, al-Masry al-Youm reported Tuesday.
A source from Egypt's Public Prosecution said the verdict would be appealed.
The men were accused of responsibility for the deaths of protesters on January 28, 2011 during the revolution that ousted former Egyptian President Hosni Mubarak.
At least 800 protesters were killed and thousands of others were injured during the entire uprising.
On Sunday, Egypt's Court of Cassation ordered a retrial for Mubarak, his interior minister and six of his top security deputies after prosecutors challenged verdicts clearing them of some of the charges.
Gingrich: Debt limit wrong battlefield
WASHINGTON, Jan. 15 (UPI) -- Republicans picked the wrong battle to threaten letting the United States to go into default to achieve deficit reductions, ex-House Speaker Newt Gingrich said.
"[In] the end, it's a fight they can't sustain," Gingrich, who unsuccessfully sought the GOP presidential nomination last year, said Tuesday on CBS' "Good Morning."
"No one is going to default," the Georgia Republican said. "No one is going to allow the United States to not pay its bills. No one is going to accept the economic costs. It rallies the entire business community to the president's side."
Gingrich said congressional Republicans have two better arenas in which to make their stand: the continuing resolution funding government that expires in March, and the sequester, which automatically cuts spending across the board unless it's addressed.
"[Those] two fronts they can fight, and they have much less resistance from the average American and it's much harder for the president to oppose them," Gingrich said.
Outgoing Treasury Secretary Timothy Geithner said in early January Congress must increase the debt limit within the next 10 weeks after Washington reached its authorized borrowing limit of about $16.4 trillion Dec. 31.
Notable deaths of 2014 [PHOTOS]