"The most urgent threat that he'll have to deal with and other presidents after him will have to deal with is an attack on our homeland," Bush said in his final news conference. "You know, I wish I could report that's not the case, but there's still an enemy out there that would like to inflict damage on America. And that'll be the major threat."

While Iraq is relatively calm, Bush said North Korea remained a problem and "there's a debate in the intel community about how big" as he assessed what he once called the "axis of evil."

A main concern in North Korea, engaged in denuclearizing the Korean peninsula, is there may be a highly enriched uranium program, which makes a strong verification regimen vital.

"In other words, in order to advance our relations with North Korea, the North Korean government must honor the commitments it made to allow for strong verification measures to be in place to ensure that they don't develop a highly enriched uranium program, for example," Bush said. "So they're still dangerous and Iran is still dangerous."