The US has killed the leader of al-Qaeda, Ayman al-Zawahiri
Ayman al-Zawahiri was killed in a counter-terrorism operation carried out by the CIA in the Afghan capital Kabul on Sunday.
Number two to Osama Bin Laden together they plotted and carried out the 9/11 attacks and he remained one of America's most wanted terrorists.
Mr Biden said al-Zawahiri had "carved a trail of murder and violence against American citizens".
"From hiding, he co-ordinated al-Qaeda's branches and all around the world, including setting priorities for providing operational guidance and calling for and inspired attacks against US targets," the president said in a live television address from the White House.
"Now justice has been delivered and this terrorist leader is no more," added Biden.
The FBI updated its Most Wanted Terrorist poster on Monday with Zawahiri's status: "Deceased."
The 71-year-old Egyptian doctor took over al-Qaeda after the death of Bin Laden in 2011.
Mr Biden said he had given the final approval for the "precision strike" after months of planning.
Officials said Zawahiri was on the balcony of a safe house when the drone fired two missiles at him.
Other family members were present, but they were unharmed and only Zawahiri was killed in the attack, they added.
"Zawahiri's killing will bring closure to families of the nearly 3,000 victims of the 2001 attacks in which hijackers crashed passenger jets into landmark buildings in New York and Washington - including two skyscrapers in Manhattan," said Biden.
Some 344 firefighters were also killed. Andrew Ansbro, president of the New York Firefighters Association thanked Mr Biden for "helping to bring another level of closure to all impacted by these attacks".
Mr Biden said that Zawahiri had also masterminded other acts of violence, including the suicide bombing of the USS Cole naval destroyer in Aden in October 2000 which killed 17 US sailors, and the 1998 attacks on the US embassies in Kenya and Tanzania, in which 223 people died.
Ayman al-Zawahiri came from a Distinguished family
Born in the Egyptian capital, Cairo, on 19 June 1951, Zawahiri came from a respectable middle-class family of doctors and scholars.
His grandfather, Rabia al-Zawahiri, was the grand imam of al-Azhar, the centre of Sunni Islamic learning in the Middle East, while one of his uncles was the first secretary-general of the Arab League.
Zawahiri became involved in political Islam while still at school and was arrested at the age of 15 for being a member of the outlawed Muslim Brotherhood - Egypt's oldest and largest Islamist organisation.
His political activities did not, however, stop him from studying medicine at Cairo University's medical school, from which he graduated in 1974 and obtained a masters degree in surgery four years later.
His father Mohammed, who died in 1995, was a pharmacology professor at the same school. A
FBI Most Wanted List Description
Murder of U.S. Nationals Outside the United States; Conspiracy to Murder U.S. Nationals Outside the United States; Attack on a Federal Facility Resulting in Death
Aliases: Abu Muhammad, Abu Fatima, Muhammad Ibrahim, Abu Abdallah, Abu al-Mu'iz, The Doctor, The Teacher, Nur, Ustaz, Abu Mohammed, Abu Mohammed, Nur al-Deen, Abdel Muaz, Dr. Ayman al Zawahir
The Rewards For Justice Program, United States Department of State, is offering a reward of up to $25 million for information leading directly to the
apprehension or conviction of Ayman Al-Zawahiri.
Al-Zawahiri is a physician and the founder of the Egyptian Islamic Jihad (EIJ). This organization opposes the secular Egyptian Government and seeks its
overthrow through violent means. In approximately 1998, the EIJ led by Al-Zawahiri merged with Al Qaeda.
Ayman Al-Zawahiri has been indicted for his alleged role in the August 7, 1998, bombings of the United States Embassies in Dar es Salaam, Tanzania, and
SHOULD BE CONSIDERED ARMED AND DANGEROUS
If you have any information concerning this person, please contact your local FBI office or the nearest American Embassy or Consulate.
Building believed to be the location where Ayman Al-Zawahiri was hit by missile strike (Source Twitter)