WASHINGTON: President Joe Biden announced Monday that the United States had killed Al-Qaeda chief Ayman al-Zawahiri, one of the world's most wanted terrorists and suspected mastermind of the September 11, 2001 attacks.

In a televised address, Biden said the strike in Kabul, Afghanistan had been carried out on Saturday. "I gave the final approval to go get him," he said, adding that there had been no civilian casualties.

"Justice has been delivered and this terrorist leader is no more," Biden said.

A senior administration official said Zawahiri had been killed on the balcony of a house in Kabul in a drone strike, and that there had been no US boots on the ground in Afghanistan.

The official said that Zawahiri's presence in the Afghan capital Kabul was a "clear violation" of a deal the Taliban had signed with the US in Doha in 2020 that paved the way for the US withdrawal from Afghanistan.

It was the first known over-the-horizon strike by the United States on an Al-Qaeda target in Afghanistan since American forces withdrew from the country on August 31, 2021.

Zawahiri, an Egyptian surgeon, had been on the run for 20 years since the 9/11 attacks that killed nearly 3,000 people in the United States.

He took over Al-Qaeda after Osama bin Laden was killed by US special forces in Pakistan in 2011, and had a $25 million US bounty on his head.

Over the weekend the Afghan interior ministry denied reports circulating on social media of a drone strike in Kabul, telling AFP a rocket struck "an empty house" in the capital, causing no casualties.

Early Tuesday in Kabul, however, Taliban spokesman Zabihullah Mujahid tweeted that an "aerial attack" was carried out on a residence in the Sherpur area of the city.

"The nature of the incident was not revealed at first. The security and intelligence agencies of the Islamic Emirate investigated the incident and found in their preliminary investigations that the attack was carried out by American drones," his tweet said.

In recent months the Taliban have largely barred media from covering the aftermath of security incidents and frequently deny or downplay any casualties.

The news comes a month before the first anniversary of the final withdrawal of US troops from Afghanistan, leaving the country in the control of the Taliban insurgency that fought Western forces over the preceding two decades.