President Bush has acknowledged that his administration's decisions have contributed to instability in Iraq.
In an interview with the CBS news magazine 60 Minutes broadcast Sunday, Mr. Bush said history will find ways the United States could have done things better in Iraq.
But Mr. Bush stood by his decision to remove former Iraqi leader Saddam Hussein. Mr. Bush called Saddam "a significant source of instability."
Mr. Bush added that he believes the Iraqi people owe the American people a "huge debt of gratitude" and he believes most Iraqis are grateful U.S. forces removed Saddam.
In the interview, Mr. Bush also said failure in Iraq would empower Iran, calling the Islamic Republic "a significant threat to world peace."
He said U.S. forces would deal with any Iranians in Iraq that are found to be harming U.S. or Iraqi citizens.
Mr. Bush filmed the interview after announcing his plan to send more than 20,000 additional U.S. soldiers to Iraq.
Some information for this report was provided by AFP, AP and Reuters.