President Obama hailed the announcement today by the Libyan government that longtime dictator Moammar Gadhafi was killed, calling it a historic victory for the Libyan people.
"Today we can definitively say that the Gadhafi regime has come to an end," the president said this afternoon.
"This is a momentous day in the history of Libya," he added. "The dark shadow of tyranny has been lifted."
While Obama did not independently confirm Gadhafi's death, the White House said it had confidence in the reports coming out of Libya.
The president warned that Libya will face a "long and winding road to democracy," but vowed U.S. support in coming months.
"This marks the end of a long and painful chapter for the people of Libya, who will now have the opportunity to determine their own destiny in a new and democratic Libya," the president said. "You have won your revolution."
Obama authorized U.S. military action in Libya in March, saying at the time that NATO would take the lead in the engagement but that the U.S. would not "stand idly by in the face of actions that undermine global peace and security."
Vice President Joe Biden said earlier today that the U.S. spent $2 billion on the military engagement.
"The people of Libya have gotten rid of a dictator," Biden said at an event in New Hampshire. "This is one tough, not-so-nice guy."
Though details of Gadhafi's death are murky, the National Transition Council said Gadhafi, the flamboyant dictator who terrorized his country and much of the world during his 42 years of despotic rule, was killed in a fight between his supporters and rebels in the town of Sirte, where he was born and which was a stronghold of his supporters.
Prior to that gunfight, NATO's jet fighters struck two military vehicles "which were part of a larger group that was maneuvering in the vicinity of Sirte conducting military operations that presented a clear threat to civilians," a NATO official said. But Gadhafi was not part of that convoy, per the NTC.
An NTC fighter carrying a golden pistol he claimed belonged to the eccentric leader told reporters that Gadhafi pleaded to him not to shoot.
Libya's Prime Minister Mahmoud Jibril said that Gadhafi died of a bullet wound to his head, and was dead before reaching the hospital. Jibril added that there was no order to kill him and that officials would have preferred bringing Gadhafi in alive.
But a dramatic video aired on several Arab news stations showed a different story. The dramatic video allegedly taken when Gadhafii was captured shows him haggard and bloodied, surrounded by a chaotic crowd of young men. Shots are heard in the background as Gadhafi is taken from a car by armed rebels.
Al Jazeera aired another video of what appeared to be the dead leader, showing Gadhafi lying in a pool of blood in the street, shirtless, and surrounded by people.
National Transition Council leaders said Gadhafi's son, Motassim, was also killed though another son, Saif Al-Islam, fled Sirte in a convoy. Three of Gadhafi's eight children are in Algeria, and NTC leaders say they will ask the neighboring country to send them back.
"We have been waiting for this moment for a long time. Moammar Gadhafi has been killed," Jibril said at a news conference in Tripoli.
He added that the rebel government will wait until later today or Friday to officially declare what it calls a state of liberation.
Word of Gadhafi's death triggered celebrations in the streets of Tripoli with insurgent fighters waving their weapons and dancing jubilantly.
Gadhafi had been on the run for weeks after being chased out of the capital Tripoli by NATO bombers and rebel troops.
He was believed to be hiding in the vast Libyan desert while calling on his supporters to rise up and sweep the rebel "dogs" away. But his once fearsome power was scoffed at by Libyans who had ransacked his palace compound and hounded him into hiding.
While reports of Gadhafi's death have been met with jubilation, Libya now faces a new challenge of establishing a government.
"Let us recognize immediately that this is only the end of the beginning," UN Secretary-General Ban Ki-moon said today.
Gadhafi, 69, ruled Libya with an iron fist for almost 42 years. He seized control of the country in Sept., 1969 in a bloodless coup when he was just 27 years old. The then young and dashing army captain and his small band of military officers overthrew the monarch King Idris, setting up a new Libyan Arab Republic that over the years became increasingly isolated from the rest of the world.
Gadhafi became an advocate of Arab and African unity, and openly declared his vision for a "United States of Africa." But his relationship with the western world was strained and Gadhafi instead became known as the top sponsor of terrorism and for harboring international fugitives.
At the height of his ability to threaten terrorism, President Ronald Reagan dubbed Gadhafi the "mad dog of the Middle East."
He was accused of backing the 1986 bombing of a Berlin disco popular with American soldiers, reportedly funding the hijacking of the cruise ship Achille Lauro in 1985, and the 1988 bombing of Pan Am Flight 103, which resulted in the U.N. and United States imposing sanctions on Libya.
For years, Gadhafi refused to take responsibility for the bombing, but that changed in 2003 when he acknowledged his role and tried to make amends.
Western nations established diplomatic relations with Libya in 2003 after Gadhafi agreed to give up weapons of mass destruction.
The eccentric leader, who amassed power and wealth by controlling the nation's oil industry, held the title of being the longest-serving leader in Africa and the Arab world.
Over the years, Gadhafi earned an international reputation for his outlandish apparel and much-ridiculed phobias and proclivities.
In U.S. diplomatic cables recently released by WikiLeaks, Gadhafi was described as a "mercurial and eccentric figure who suffers from severe phobias, enjoys flamenco dancing and horse racing, acts on whims and irritates friends and enemies alike."
He was "obsessively dependent on a small core of trusted personnel," especially his longtime Ukrainian nurse Galyna, who has been described as a "voluptuous blonde," according to the cables.
Among his other unusual behaviors, the Libyan leader reportedly feared flying over water, didn't like staying on upper floors and traveled with a "pistol packing' posse" of female bodyguards.
ABC News' Luis Martinez contributed to this report.