“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”.
A Taliban spokesman described the US operation as a clear violation of international principles.
“Such actions are a repetition of the failed experiences of the past 20 years and are against the interests of the United States of America, Afghanistan and the region,” the spokesman added.
Zawahiri, an eye surgeon who helped found the Egyptian Islamic Jihad militant group, took over the leadership of al-Qaeda following the killing by US forces of Bin Laden in May 2011.
Before that, Zawahiri was often referred to as Bin Laden’s right-hand man and the chief ideologue of al-Qaeda.
He is believed by some experts to have been the “operational brains” behind the 11 September 2001 attacks in the United States.
Source: BBC News