The United States is vowing to capture and kill new al-Qaida leader Ayman al-Zawahri, just as it did his predecessor, Osama bin Laden.

The chairman of the Joint Chiefs of Staff, Admiral Mike Mullen, made the pledge Thursday, saying the Egyptian surgeon turned terrorist leader should expect the same treatment as bin Laden. U.S. commandos killed him in a raid on his Pakistani hideout in early May.

U.S. Defense Secretary Robert Gates noted that al-Qaida remains committed to carrying out terrorist attacks against the U.S. and other Western interests, as well as Israel. But he said Zawahri lacked the “peculiar charisma” that bin Laden possessed. Gates said bin Laden was “much more operationally engaged” than Zawahri.

An unnamed senior U.S. official said Zawahri has not had any combat experience and lacks “strong leadership or organizational skills.”

Earlier Thursday, al-Qaida announced that Zawahri would take over the global terror network.

Zawahri turns 60 on Sunday and had been bin Laden's long-time deputy. Terrorism experts often consider him to be al-Qaida's main strategist. He is believed to be operating from somewhere in the mountainous region near the Pakistan-Afghanistan border.

Zawahri comes from an upper middle class family of doctors and scholars, but became involved in radical Islam as a teenager. While earning a medical degree, he helped form the Egyptian Islamic Jihad militant group.

After bin Laden was killed, Zawahri lauded the mastermind of the 2001 terrorist attacks on the U.S. Zawahri said that bin Laden “went to his God as a martyr.”

Zawahri also criticized Arab states al-Qaida considers to be godless and too closely allied with the U.S. He pledged allegiance to the leader of the Afghan Taliban, Mullah Omar, and described him as the “Emir of Believers.”