"We in the Al-Qaeda organisation pledge to Allah the almighty and ask his help, support and steadfastness to continue on the path of jihad, the path walked upon by our leaders, and on top of them, Sheikh Osama," SITE said quoting the statement.
Al-Qaeda said it will also soon release an audiotape of bin Laden that was recorded a week before he was killed by US commandos in Pakistan.
"We also stress that the blood of the mujahid Sheikh Osama bin Laden, may Allah have mercy upon him, weighs more to us and is more precious to us and to every Muslim than to be wasted in vain," it said.
"We call upon our Muslim people in Pakistan, on whose land Sheikh Osama was killed, to rise up and revolt to cleanse this shame that has been attached to them by a clique of traitors and thieves who sold everything to the enemies.
"(We call upon them) to rise up strongly and in general to cleanse their country (Pakistan) from the filth of the Americans who spread corruption in it," said the statement.
The statement came after US President Barack Obama said that American commandos killed bin Laden on Sunday in a covert operation in the Pakistani garrison town of Abbottabad.
Soon after Obama's announcement, the Shumukh al-Islam forum, which had been a conduit for Al-Qaeda announcements, had asked users to wait for confirmation of his death, but many had posted threats against the US to avenge the killing.
The latest statement promised that America and those who live in the US "will never enjoy security until our people in Palestine enjoy it."
The formal Qaeda statement came four days after the Al-Qaeda branch in bin Laden's ancestral home of Yemen said they had confirmation through their contacts in Pakistan that he had been killed.
Saudi and Yemeni Al-Qaeda branches which merged in January 2009 to form the Yemen-based Al-Qaeda in the Arabian Peninsula (AQAP) said on Monday that bin Laden had been killed."
"This news has been a catastrophe for us. At first we did not believe it, but we got in touch with our brothers in Pakistan who have confirmed it," said an AQAP member reached by telephone.
The killing of bin Laden was hailed by most countries in the Middle East and any public outpouring of sympathy for bin Laden or anger against the killing has been muted in a region swept by uprisings against autocratic rule.
