President Bush's choice to head the Federal Bureau of Investigation says his top priority is to restore public confidence in an agency plagued by some high-profile mistakes in recent years. Robert Mueller made the comments during the opening of Senate confirmation hearings Monday.

The president's choice of Robert Mueller to head the FBI has been praised by Republicans and Democrats alike. And Mr. Mueller sought to build on that support Monday, as he set out priorities for a law enforcement agency that has come under fire in recent years for some highly publicized blunders. "If I have the honor of being confirmed by the Senate," Mr. Mueller said, "I will make it my highest priority to restore the public's confidence in the FBI, to re-earn the faith and trust of the American people."

Public confidence in the FBI has been slipping in recent years, due to a series of investigative and bureaucratic mistakes. These include the recent failure of the FBI to provide documents to lawyers for Oklahoma City bomber Timothy McVeigh, resulting in a one-month delay in his execution.

Other incidents that have tarnished the FBI's once sterling reputation include the revelation that former high-level FBI agent Robert Hanssen was a spy for Russia and the bungling of the investigation into the espionage case involving former nuclear scientist Wen Ho Lee.

In addition, the FBI remains on the defensive for its conduct in two armed standoffs in the early 1990s, one in Ruby Ridge, Idaho, and the other at the Branch Davidian compound in Waco, Texas.

Robert Mueller says if confirmed as the next FBI Director, he will insist on openness about the bureau's shortcomings. "We must tell the truth and let the facts speak for themselves," he said. "The truth is what we expect in our investigations of others and the truth is what we must demand of ourselves when we come under scrutiny."

Members of the Senate Judiciary Committee seemed pleased with what they heard from Mr. Mueller. Committee Chairman Patrick Leahy (D-Vt.) says there is no question that Mr. Mueller faces a difficult task. "We have long thought that the FBI was the crown jewel of law enforcement agencies," Senator Leahy said. "Some of that jewel has lost some of its luster and we want to restore it. So frankly, Mr. Mueller, you have both a great challenge and a great opportunity to restore public confidence in the bureau and it is safe to say that all of us want to do that."

Mr. Mueller's predecessor, Louis Freeh, was popular with members of Congress. But that did not stop lawmakers from complaining about what they saw as a culture of arrogance at the FBI, that seemed to insulate the agency from congressional and public criticism.

Iowa Republican Senator Charles Grassley is urging Robert Mueller to make sweeping changes. "The FBI is in desperate need of a director who will make drastic changes to the bureau's management culture," Senator Grassley said. "This person must be able to sweep out the culture of arrogance and replace it with a culture dedicated to truth and honorable service to the American people."

Robert Mueller is a career prosecutor who has handled some high-profile cases for the Justice Department. He oversaw the investigation into the 1988 bombing of Pan Am flight 103 over Scotland and the prosecution of former Panamanian President Manuel Noriega who was convicted on cocaine trafficking charges in 1992.

The Senate is expected to confirm Mr. Mueller as the FBI's sixth director sometime in the next few weeks.