Barack Obama yesterday renewed his case for ending the war in Iraq and refocusing attention on Afghanistan ahead of his forthcoming trip to the two countries and amid an intensifying debate with John McCain, his Republican presidential rival, over the US "war on terror".

The Democratic presidential candidate said he remained committed to withdrawing all combat troops from Iraq within 16 months of taking office, arguing that the security gains of the past year had failed to repair the damage caused to US interests by the war.