Al-Qaeda has selected its longtime No. 2 to succeed Osama bin Laden following last month's U.S. commando raid that killed the group's leader, according to a statement posted Thursday on a website affiliated with the network.

Ayman al-Zawahri, who turns 60 on Sunday, has long brought ideological fire, tactics and organizational skills to al-Qaeda. The surgeon by training has promoted the use of suicide bombings and independent cells that have become the network's trademarks.

He is believed to be living somewhere near the Pakistan-Afghanistan border and has appeared in dozens of videos and audiotapes in recent years, increasingly becoming the face of al-Qaeda as bin Laden kept a lower profile.

The two leaders first crossed paths in the late 1980s in the caves of Afghanistan, where al-Zawahri reportedly provided medical treatment to bin Laden and other Islamic fighters battling Soviet forces. Their alliance would develop years later into the al-Qaeda network blamed for the Sept. 11, 2001, attacks on the U.S.

In a videotaped eulogy released earlier this month, al-Zawahri warned that America faces not individuals or groups but an international community of Muslims that seek to destroy it and its allies.   

"Today, praise God, America is not facing an individual, a group or a faction," he said, wearing a white robe and turban with an assault rifle leaning on a wall behind him. "It is facing a nation than is in revolt, having risen from its lethargy to a renaissance of jihad."  

Al-Zawahri also heaped praise on bin Laden, who was killed in a May 2 raid by U.S. Navy SEALs in the Pakistani garrison town of Abbottabad, and criticized the U.S. for burying him at sea.  

"He went to his God as a martyr, the man who terrified America while alive and terrifies it in death, so much so that they trembled at the idea of his having tomb," he said.

Al-Qaeda gave no details about the selection process for bin Laden's successor but said that it was the best tribute to the memory of its "martyrs."

The statement announcing al-Zawahri's succession was filled with the network's usual rhetoric, vowing to continue the fight against what it called "conquering infidels, led by America and its stooge Israel, who attack the homes of Islam." 

The group also said it will never accept Israel's legitimacy and will continue to support Muslims in Afghanistan, Iraq and North Africa. 

The al-Qaeda statement also stated the group's support for this year's popular uprisings in Egypt, Tunisia, Yemen, Syria and Libya.  

"We encourage the people of Islam to rise up and continue the struggle, persistence and devotion until all the corrupt and oppressive regimes imposed by the West are gone," it said.