President George W. Bush said the biggest regret of his presidency was "the intelligence failure in Iraq," he told ABC "World News" in an interview airing on Monday. "A lot of people put their reputations on the line and said the weapons of mass destruction is a reason to remove Saddam Hussein," he said, adding that he was unprepared for war when he took office.

Bush leaves the White House on Jan. 20 with public approval ratings near record lows partly due to the unpopular Iraq war that toppled Iraqi leader Saddam Hussein after the US-led invasion in March 2003. (Reuters)