US Vice President Dick Cheney has admitted he was wrong when he said the insurgency in Iraq was in its "last throes" more than two years ago.
But he insisted that the Bush administration would still commit troops to Iraq if it had a second chance, even though more than 3,000 US military personnel have been killed.
In an interview on CNN's Larry King Live, Cheney defended President George Bush's Iraq policy but made the most direct public admission yet of how the US administration had underestimated the strength of opposition in Iraq.
Cheney said he no longer believed his May 2005 assessment in which he said: "I think they're in the last throes, if you will, of the insurgency."
He told Larry King Live: "My estimate at the time - and it was wrong, it turned out to be incorrect - was the fact that we were in the midst of holding three elections in Iraq, elected an interim government, then ratifying a constitution, then electing a permanent government, that they had had significant success, we'd rounded up Saddam Hussein.
"I thought there were a series of these milestones that would in fact undermine the insurgency and make it less than it was at that point. That clearly didn't happen. I think the insurgency turned out to be more robust."
Cheney added that the assessment, which has been widely mocked, was made before al-Qaida stepped up attacks in Iraq, including the 2006 bombing of a Shi'ite mosque that sparked a wave of sectarian killings.
But he went on: "I firmly believe that the decisions we've made with respect to Iraq and Afghanistan have been absolutely the sound ones in terms of the overall strategy."
Cheney also said that he expects a pivotal September report on the war in Iraq to show "significant progress", a position which puts him ahead of President Bush, who has refused to speculate on the report's content.