"Saudi security was actively following the movements of most of the terrorists with precision," Bandar, the national security advisor to Saudi King told the Arabic satellite network, Al-Arabiya, Thursday.
"If U.S. security authorities had engaged their Saudi counterparts in a serious and credible manner, in my opinion, we would have avoided what happened," Bandar said.
Former White House counterterrorism official Dick Clarke dismissed Bandar's statement as untrue. "The Saudis were uncooperative and did not engage in significant info sharing on al Qaeda prior to 9/11 despite repeated U.S. attempts to engage them," said Clarke.
Another former intelligence official said there is no reason to believe the Saudi government was tracking the 9/11 hijackers.
Almost 3,000 people in New York, Washington and Pennsylvania died in the 9/11 attacks. Fifteen of the 19 suicide hijackers were Saudi nationals who received U.S. visas in Saudi Arabia, according to the 9/11 Commission Report.
The Saudi Embassy has not responded to ABC News' requests for comment.