Al-Qaeda number two Ayman Zawahiri warned US president-elect Barack Obama against sending more troops to Afghanistan, in an Internet audiomessage released on Wednesday.

"What you have announced before ... that you will withdraw (US) troops from Iraq (and send them) to Afghanistan is a policy that is doomed to failure," Zawahiri said in the message made available by the SITE Intelligence Group.

"If you still want to be stubborn about America''s failure in Afghanistan, then remember the fate of (US President George W.) Bush and (Pakistan''s former president) Pervez Musharraf, and the fate of the Soviets and British before them," he added.

In a major interview aired on Sunday, Obama vowed no retreat from his campaign promise to begin pulling troops out of Iraq and switch the military focus to Afghanistan.