The American president insists "justice has been delivered"
Joe Biden has confirmed the US has killed the leader of al-Qaeda.
Ayman al-Zawahiri was targeted in a drone strike in Afghanistan on Sunday.
He was one of the masterminds of the 9/11 terror attacks.
The American president insists "justice has been delivered. And this terrorist leader is no more."
Biden said: "He carved a trail of murder and violence against American citizens, American service members, American diplomats, and American interests"
Sky's US correspondent Mark Stone says the operation to capture or kill him began months ago.
"US intelligence has clearly been trying to find this man for many many years and at the beginning of this year it became clear his wife and children had relocated from where there were believed to be in Pakistan to Afghanistan and to the Afghan capital, Kabul."
The president said that after he considered "clear and convincing evidence" of al-Zawahiri's location, he "authorized a precision strike that would remove him from the battlefield once and for all."
He gave his final approval to "go get him" one week ago.
