Al-Qaida's No. 2 leader, Ayman al-Zawahri, has said that five years of US occupation of Iraq had brought only "failure and defeat", according to a new audio tape released Thursday on a website known for militant messages.

US President George W. Bush will pass on the "problem" to his successor, al-Zawahri added.

The militant leader said Bush's decision to accept advice to postpone further troop withdrawals from Iraq until after July was just a cover-up for his failure.

Bush announced last week that he has adopted top US commander in Iraq David Petraeus' proposal to suspend further US troop withdrawals from Iraq beyond July.

Bush said he made the decision after Petraeus requested additional time to assess whether the US military can maintain the recent security improvements with fewer troops on the ground.

The authenticity of the tape could not be independently verified.

(Xinhua News Agency April 18, 2008)