The leader of al-Qaeda, Ayman al-Zawahiri, has been killed by the US drone strike in Afghanistan.
Al-Zawahiri became the leader of al-Qaeda following the killing of Osama Bin Laden in May 2011.
President Joe Biden said Zawahiri had “carved a trail of murder and violence against American citizens”.
“Since the United States delivered justice to bin Laden 11 years ago, Zawahiri has been a leader of al-Qaeda,” Mr Biden said. “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.”
“Now justice has been delivered and this terrorist leader is no more,” he added.
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.
Mr Biden said he had given the final approval for the “precision strike” on the 71-year-old Egyptian after months of planning.
His killing will bring closure to families of the nearly 3,000 victims of the 2001 attacks, Mr Biden added.
“No matter how long it takes, no matter where you hide, if you are a threat to our people, the United States will find you and take you out,” said Mr Biden, adding that “we shall never waver from defending our nation and its people”.
Mr Biden said 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.
He insisted that Afghanistan would never again become a safe haven for terrorists.