Cairo: Ayman al-Zawahiri, the Egyptian surgeon-turned-jihadist ideologue, was on Thursday named the new chief of al-Qaeda to succeed its slain leader Osama bin Laden.

Al-Zawahiri, 59, one of the founders of al-Qaeda, has played a defining role in the militant group for more than a decade as bin Laden's deputy. Even before the announcement, he
had been widely regarded as the organisation's de facto leader and public face.

The announcement, dated June 2011 but which surfaced today on the jihadist sites, said the decision to appoint al-Zawahiri, who is carrying a USD 25 million reward on his head, was made to pay respect to the "righteous martyrs" and to honour the legacy of bin Laden.

"Hereby the General Command of the Qaeda al-Jihad --and after the end of the consultations -- we declare that Sheikh Dr Abu Muhammad Ayman al-Zawahiri (May God bless him) will take over the responsibility of command of the group," CNN quoted the statement as saying.

The statement said under Zawahiri's leadership al-Qaeda would relentlessly pursue its "jihad" (holy war) against the United States and Israel.

"We seek with the aid of God to call for the religion of truth and incite our nation to fight ... by carrying out jihad against the apostate invaders ... with their head being crusader America and its servant Israel, and whoever supports them," said the statement.

The fight would continue "until all invading armies leave the land of Islam". The extremist network affirmed that it would not "recognise any legitimacy of the so-called state of Israel."

"We will not accept or adhere to any agreement or accord that recognises it (Israel) or that robs a mile from Palestine, whether it is the United Nations controlled by top criminals or any other organisation".

Al-Zawahiri is believed to run al-Qaeda operations from the Pakistan-Afghanistan border region.

Al-Zawahiri had issued a eulogy for bin Laden last week saying al-Qaeda's leader had terrified the US when he was alive and would continue to do so in death.

He appeared in a white Arab robe and turban, a Kalashnikov at his side, in the 28-minute video posted on jihadist online forum. "We will pursue the jihad until we expel the invaders from Muslim lands," he had said.

Bin Laden was killed in a US raid on his compound in Abbottabad near Islamabad on May 2.

The statement also said the group will not shift its policy and pledged its support to, among others, Taliban chief Mullah Omar.

Al-Qaeda also voiced its "support (to) the uprisings of our oppressed Muslim people against the corrupt and tyrant leaders who have made our nation suffer in Egypt, Tunisia, Libya, Yemen, Syria and Morocco."

The Middle East and North Africa have witnessed a series of revolts since December that have succeeded in toppling autocratic rulers in Egypt and Tunisia. Libya's Muammar Gaddafi and Syria's Bashar al-Assad are also still battling popular uprisings in their countries.

Al-Qaeda urged those involved in the uprisings to continue their "struggle until the fall of all corrupt regimes that the West has forced onto our countries."

Al-Zawahiri, the second and last "emir" of the Egyptian Islamic Jihad, an affiliate of al-Qaeda, was wanted in the US even before the 2001 attacks targeting New York's World Trade Centre and the Pentagon, which killed over 3,000.

He was indicted in absentia in 1999 for the August 1998 bombings of US embassies in Tanzania and Kenya that killed 224 people, and was also considered the mastermind of
the October 2000 bombing of the USS Cole in Yemen, which killed 17 sailors.

Born in a wealthy family in Cairo, al-Zawahiri is a physician and founding member of the Egyptian Islamic Jihad (EIJ), a militant group that opposed the then secular Egyptian government of Hosni Mubarak and sought its overthrow through violent means.

Like bin Laden, al-Zawahiri also went to Afghanistan during their fight against the Soviets, although he was there primarily to offer his medical expertise.

By the 1990s, he refocused his attention on undermining and attacking the Egyptian government and, eventually, the US.

Zawahiri lacks Osama's charisma: US

Al Qaeda's new leader Ayman al-Zawahiri does not match his predecessor Osama bin Laden in his charisma nor does he have the slain leader's credentials, a top official of the Obama administration said in Washington on Thursday.

Hours after the announcement of al Qaeda appointing a successor to bin Laden became public, a senior Administration official was quick to point out that given the baggage
al-Zawahiri was carrying, it was unlikely that he would enjoy the position bin Laden did in the extremist network.

However, there was no immediate reaction from either the White House or the State Department on the announcement by a jihadist website that al-Zawahiri will now head the network that orchestrated the 9/11 attacks.

"The bottom line is that Zawahiri has nowhere near the credentials that Osama bin Laden had," the official said, preferring anonymity.

Al-Zawahiri has not demonstrated strong leadership or organisational skills during his time in al Qaeda or previously in the Egyptian Islamic Jihad, the official said, adding that his ascension to the top spot will likely generate criticism if not alienation and dissension with al-Qaeda.

"No matter who is in charge, he will have a difficult time leading al Qaeda while focusing on his own survival as the group continues to hemorrhage key members responsible for
planning and training operatives for terrorist attacks," the official said.