Nashua, N.H. ? President Bush on Thursday flatly rejected charges that he did not grasp the danger to the United States posed by al-Qaida terrorists before Sept. 11, 2001, a claim his former counterterrorism chief made this week before a commission studying the terror attacks.

“Had I known that the enemy was going to use airplanes to strike America, to attack us, I would have used every resource, every asset, every power of this government to protect the American people,” Bush said.

Bush delivered those remarks, his most extensive yet on the matter, without prompting at the start of a “conversation” on the economy at the New Hampshire Community Technical College here.

His comments came a day after Richard Clarke, a former top national security official in the Bush White House and previous administrations, told an independent commission that Bush had failed to fully appreciate the urgent need to take action against al-Qaida and Osama bin Laden. The commission was created by Congress to study government failures preceding the 9-11 attacks and its actions afterward.

Before launching into an hourlong discussion on the economy, Bush touted the actions he took to protect the nation after the attacks, such as the massive government reorganization that led to the creation of the Department of Homeland Security.

“We’re trying to do our solemn duty to protect America,” Bush said.

He cast the U.S.-led invasion of Iraq as part of those efforts.

“Part of the war on terror … is broader than just al-Qaida. … You see, the lesson of September the 11th is we must deal with threats before they fully materialize. You can’t just see a threat and hope it goes away,” the president said, before calling former Iraqi leader Saddam Hussein “a threat to America or anybody else who loved freedom.”