"We've got to talk about the kind of image we have and the things we do to create that image," said Kean. "If we don't, there's going to be more terrorists created than the ones we're now killing."
It is up to President Bush and Congress to enact the necessary reforms, both men said.
White House national security adviser Stephen Hadley said the Bush administration accepted a large majority of the panel's recommendations, but he acknowledged that the job of implementation is incomplete.
"Obviously, as we've said all along, we are safer, but not yet safe. There is more to do," Hadley told "Fox News Sunday."
The 9/11 panel -- formally known as the National Commission on Terrorist Attacks Upon the United States -- disbanded as a government entity the month after its report was issued.
But the 10 members formed the Public Discourse Project, with the aim of fulfilling their original mandate of protecting against future terrorist attacks.