Mr. Bush was initially opposed to having the program investigated in a public format, but made it clear that he is resigned to open hearings that are scheduled to begin in coming weeks.
Mr. Bush's decision to authorize the National Security Agency to monitor — without warrants — people inside the United States has sparked a flurry of questions about the program's legal justification.
In defending his authorization of warrantless wiretaps, Mr. Bush said key members of Congress were briefed on the program and had the chance to express their approval or disapproval. But a few of the Democrats who were briefed say that's not true, saying they were only informed of the program and had no meaningful way challenge its legality, reports CBS News correspondent Mark Knoller.
The president defended the program during a campaign-style town hall meeting, saying he understands concerns about it but monitoring the phone calls of affiliates of the terrorist network al Qaeda is necessary to protect the United States. He said he made sure he had the legal authority to allow the program before he did so.
"There will be a lot of hearings to talk about that, but that's good for democracy," he said. "Just so long as the hearings, as they explore whether or not I had the prerogative to make the decision I make, doesn't tell the enemy what we're doing. See, that's the danger."
In the days after the program's existence was revealed, Mr. Bush cautioned against hearings, arguing that the appropriate members of Congress were being consulted privately and offering assurances that he was working within the law to authorize the eavesdropping.
"Any public hearings on programs will say to the enemy, `Here's what they do — adjust.' This is a war," Mr. Bush said at a December news conference when asked about expected hearings on Capitol Hill.
The Senate Judiciary Committee has scheduled hearings on the issue for early February. The Senate Intelligence Committee also plans to hold hearings that will be closed to the public.
For the second time in a month, Mr. Bush took questions from audience members during an appearance to win support for his war on terror.
In his opening remarks, he defended the global war on terrorism and the U.S. effort in Iraq. He said insurgents in Iraq were trying to drive the United States out through violence and bloodshed but he declared, "They're not going to shake my will."
While saying he wanted to bring American troops home, he said, "I don't want them to come home without achieving the victory."
In a question and answer session, Mr. Bush was asked about Iraq, education priorities, immigration, the economy, health care and other subjects. He said the war on terrorism would not end with an enemy surrender, as was the case in World War II. "I don't envision a signing ceremony on the USS Missouri," he said. "The peace won't be the kind of peace we're used to."
White House press secretary Scott McClellan said questions from the audience were not prescreened, and Mr. Bush himself said that while the event was about terrorism, no questions were off limits.
Kentucky, where Iraq is taking center stage in politics, provided an appropriate backdrop for Mr. Bush's remarks.
Kentucky Rep. Anne Northup, a Republican ally of the president who joined him at the event, describes the situation in Iraq as "painful." Yet, she stands firmly behind his decision to invade that country, a potentially divisive issue in Northup's upcoming re-election campaign.
In contrast, Iraq war veteran Andrew Horne, a Democrat running for her seat, said the invasion was a mistake because the threat of weapons of mass destruction — a key justification for the war — never materialized.