Washington: The United States has vowed to hunt down and kill new al-Qaeda ‘emir’ Ayman al-Zawahiri like it did in the case of his predecessor Osama bin Laden.

"Zawahiri and his organisation still threaten us. As we did both seek to capture and kill and succeed in killing bin Laden, we certainly do or will do the same thing with Zawahiri," Admiral Mike Mullen, Chairman of the US Joint Chiefs of Staff, told reporters at a Pentagon news conference.
Mullen on Thursday said he was not surprised by the news reports that Zawahiri, who is carrying a USD 25 million reward on his head, has succeeded bin Laden.

Al-Qaeda has named al-Zawahiri as its new chief following the killing of long-time leader bin Laden by US commandos in May 2 raid in Pakistan.

In his last press conference as the Secretary of Defense, Gates said he is not sure it's a position anybody should aspire to be the al-Qaeda chief, under the circumstances.

"Bin Laden has been the leader of al-Qaeda, essentially since its inception. In that particular context, he had a peculiar charisma that I think Zawahiri does not have. I think he was much more operationally engaged than wehave the sense Zawahiri has been," he said.