Speaking at a Justice Department ceremony, Bush said the Patriot Act had been "vital to our success in tracking terrorists and disrupting their plans" and he urged lawmakers to renew elements of the law that will expire at the end of this year.

"We must not allow the passage of time or the illusion of safety to weaken our resolve in this new war," Bush said.

Gonzales replaced John Ashcroft, who was a lightning rod for criticism about how he applied certain provisions of the law that was passed after the Sept. 11, 2001, hijacked-airliner attacks. Renewal is certain to face a battle in Congress where concerns have been raised over whether the law has eroded civil liberties.

Sen. Russ Feingold, a Wisconsin Democrat who was the only senator to vote against the legislation, said Bush must address concerns about its impact on civil liberties.

"I am disappointed that the president is continuing to seek complete and immediate reauthorization of the USA Patriot Act, with no acknowledgment of the civil liberties concerns raised by people all across the political spectrum," Feingold said.

"Some aspects of the Patriot Act went too far and members from both parties have said they need to be re-evaluated."

ALLEGIANCE TO THE CONSTITUTION

Among more than a dozen provisions set to expire at year's end are some of the more controversial measures that relate to authority for FBI and criminal investigators to share information about terrorism cases and the FBI's power to obtain certain records in such cases.

The former White House counsel, Gonzales faced harsh questions at his confirmation hearing over whether he was involved in creating policies that contributed to the torture of foreign detainees. The U.S. Senate confirmed him with the second highest number of "no" votes for a successful nominee in that post.

Gonzales, after being publicly administered the oath of office by Justice Sandra Day O'Connor, sought to address another concern of critics that he might not act independently of the White House.

"Undeniably, the attorney general is a member of the president's Cabinet, a part of his team. But the attorney general represents also the American people, and his first allegiance must always be to the Constitution of the United States," Gonzales said.

"And so, I rise today to reassure you that I understand the special role of this office, and to commit to do my best on behalf of the American people to fulfill the confidence and trust reflected in my appointment," he said.

Bush firmly stood by his choice for the country's top law enforcement post. "As he embarks on all these duties, Attorney General Gonzales has my complete confidence," Bush said.