The source confirmed the account former Treasury Secretary Paul O'Neill gave earlier this week of Bush's desires before the World Trade Center tragedy.
ABC said their source was present in the same National Security Council meetings as O'Neill in January and February of 2001, immediately after Bush's inauguration.
"The president told his Pentagon officials to explore the military options, including use of ground forces," the official told ABC. "That went beyond the Clinton administration's halfhearted attempts to overthrow Hussein without force."
In book "The Price of Loyalty," O'Neill wrote that from the very start of his administration, Bush was focused on ousting Saddam.
Bush has said that his policy at the time was merely a continuation of the Clinton administration's stance. White House aides have suggested O'Neill, whom Bush fired in December 2002, is merely trying to sell books.
Both the official who spoke to ABC and O'Neill have acknowledged that Bush had not yet made up his mind for a ground invasion at the start of his administration.