Zawahiri had previously been rumoured to be dead but appeared in a video last year to mark the 20th anniversary of the attack.

US officials had suspected he was hiding out in Pakistan,but his return to Kabul - where he was living in a safe house with his family for months - raises questions about the Taliban’s commitment to keeping al-Qaeda out of the country.

A senior administration official,speaking on the condition of anonymity,said Zawahiri’s presence in the capital was a breach of the Doha agreement,which paved the way for the withdrawal of all NATO troops from Afghanistan,and also contained a Taliban pledge to prevent al-Qaeda from operating in areas under Taliban control.

Not only did Taliban officials know of his whereabouts,they also took steps to restrict access to the safe house in the aftermath of the strike,and to relocate his family.

“We expect them to abide by the terms of the Doha agreement,and the presence of al-Zawahiri in downtown Kabul is a violation of that. Going forward,we will continue to hold them accountable for their actions,” the US official said.

Zawahiri was killed on the balcony of the safe house in Kabul at 9.48pm on Saturday (US time). Senior officials discovered he was at the safe house earlier this year,prompting a few key intelligence agencies to start planning the highly guarded counter-terrorism operation.

Biden was briefed on the proposed mission on July 1 by key members of his cabinet,including CIA Director William Burns,Director of National Intelligence Avril Haines and National Security Adviser Jake Sullivan.

The president was briefed again on July 25,quizzing officials about the potential for civilian deaths,the impact the mission would have on the US relationship with the Taliban and America’s efforts to access Afghanistan for future counter-terrorism missions.

“One week ago,after being advised the conditions were optimal,I gave the final approval to go get him,” Biden said. “The mission was a success. His family members were not hurt and there were no civilian casualties.

“The United States continues to demonstrate our resolve and our capacity to defend the American people against those who seek to do us harm. Now we make it clear again tonight that 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.”

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