Over the weekend a missile killed Ayman al-Zawahiri who resided in Afghanistan.

The United States killed al Qaeda leader Ayman al-Zawahiri in a strike in Afghanistan over the weekend, President Joe Biden said on Monday, the biggest blow to the militant group since its founder Osama bin Laden was killed in 2011.

Zawahiri, an Egyptian surgeon who had a $25 million bounty on his head, helped coordinate the Sept. 11, 2001, attacks that killed nearly 3,000 people.

Mr. Biden confirmed in an address to the American people on Monday night that he authorised the precise attack to "take out Al-Zawahiri once and for all".

Justice has been delivered and this terrorist leader is no more, the US president said from the White House.

Al-Zawahiri, 71, was regarded as the successor to Osama Bin Laden as the leader of Al Qaeda. His death marks the biggest blow to the terrorist group since Bin Laden was killed in 2011.

The terrorist leader was killed by two Hellfire missiles while he was on the balcony of his safehouse in central Kabul, where he had been living with his family. No one else was killed in the strike, the US said.

An unmanned US drone carried out the strike at 9.48pm eastern time on Saturday July 30 (6.18am Kabul time on July 31) at Mr Biden's direction, a senior national security official said in a Monday night briefing.

A loud explosion echoed through Kabul early on Sunday morning.

The official said senior Taliban members were aware of his presence in the city, raising questions over whether Al-Zawahiri received sanctuary from the group following their takeover in August 2021.

US intelligence agents spent months building up his "pattern of life", and frequently observed him spending time on the balcony where he was ultimately killed.  

Model of Al-Zawahiri's safehouse built in White House situation room

What followed was a months-long operation to determine how to carry out a precision strike in downtown Kabul, as well as establishing the legal basis for the operation.

A model of Al-Zawahiri's safehouse was used to walk Mr Biden through potential strike options during briefings in the White House situation room.

We developed clear options for the President that he could consider that would also minimise the risk of any civilian casualties and take into account the ramification of taking such a strike in downtown Kabul, the official said.

Mr Biden received updates in May and June and held another briefing on July 25 during which he authorised the strike, which analysts said likely to have been carried out with Hellfire R9X missiles.

The official said Al-Zawahiri's family were present during the strike but were "purposely not targeted and were unharmed".

Saudi Arabia welcomed the announcement late on Monday.

Taliban knew that Al-Zawahiri lived in Kabul

The official added that senior Haqqani Taliban figures were "aware of Al-Zawahiri’s presence in Kabul'' and took actions to conceal it in the hours after the drone strike.

"The Haqqani Taliban members acted quickly to remove Zawahiri's wife, his daughter and her children to another location consistent with a broader effort to cover up that they had been living in the statehouse," the official said.

Al-Zawahiri’s presence in Kabul was a "clear violation" of the 2020 agreement the Taliban signed with the Trump administration, in which they promised not to allow Afghanistan to become a haven for international terrorism, the official said.