(Click here to watch a live stream of the statement)
Obama previously released a short written statement on Wednesday morning saying that he strongly condemned the killing of the United States ambassador to Libya.
He called the attack "outrageous," and confirmed that four Americans, including Stevens, were killed in a rocket attack on the U.S. Consulate in the city of Benghazi on Tuesday.
"Chris was a courageous and exemplary representative of the United States," Obama said.
In addition, Libya's Prime Minister Abdurrahim el-Keib apologized "to the American people and the government, and also to the rest of the world" for the "cowardly criminal act."
CNN reports that U.S. Secretary of State Hillary Clinton identified a second victim as Sean Smith. Smith was reportedly a Foreign Service information management officer who was a ten-year veteran of the State Department, a husband and a father of two.
The two other victims have not been named.
The violent crowd that formed in front of the U.S. consulate in the city of Benghazi was reportedly in response to an online film considered offensive to Islam, Libya's Deputy Interior Minister Wanis al-Sharif said Wednesday.
The U.S. mission in Egypt was also attacked Tuesday in response to the film, according to CNN. The news outlet reports that Al-Sharif said consulate security staff opened fire when they heard gunfire outside the mission.
"This led to more anger and this is when the consulate was stormed," he said, suggesting that there were elements loyal to the regime of deposed dictator Moammar Gadhafi aiming to stir up emotions among the protesters.
"Criminals managed to get in and they burned and ransacked the consulate," he said.
An unidentified contractor working at the mission told CNN that at this time the U.S. mission is very badly damaged and was being looted on Wednesday. He reportedly went on to say that he saw the bodies of all four Americans on the street Wednesday morning.
Libyan Deputy Prime Minister Mustafa Abushagur took to Twitter saying that Stevens was "a friend of Libya, and we are shocked at the the attacks on the U.S. consulate in Benghazi."
"I condemn these barbaric acts in the strongest possible terms. This is an attack on America, Libya and free people everywhere," Abushagur said.
The bodies of the four Americans are now at Benghazi airport, the contractor told CNN, citing the Libyan minister of foreign affairs and a top immigration official in Benghazi.