The US president expresses disbelief at calls for ending the Iraq occupation, suggesting 'gains' to be well worth the 'high cost in lives'.

"The successes we are seeing in Iraq are undeniable, yet some in Washington still call for retreat," claimed President George W. Bush who was addressing Pentagon officials on the occasion of the fifth anniversary of the invasion of Iraq.

"The challenge in the period ahead is to consolidate the gains we have made," he continued.

The president added that if US troops were to leave Iraq, "al-Qaeda would regain its lost sanctuaries and establish new ones fomenting violence and terror," which he claimed would bring 'serious consequences to the world economy'.

Although the Pentagon claims the number of US casualties in Iraq is just shy of 4,000, other sources maintain the toll to be much higher.