Arguing on Monday that America was still threatened by terrorists, Gonzales said at hearing to discuss the Patriot Act that al-Qaida and similar groups "still posed a grave threat to the security of the American people".
"Now is not the time to relinquish some of our most effective tools in this fight", he added.
Among more than a dozen provisions of the Patriot Act that expire at year's end are some of the more controversial measures granting FBI and criminal investigators authority to share information about terrorism cases and giving the FBI power to use secret warrants to obtain certain records.
Several Democratic senators praised Gonzales for being flexible after he said he would support changes to a portion of the law that would give subjects of certain searches the right to consult a lawyer and to challenge the warrant in court.
Some contrasted Gonzales - who only three months ago faced tough questioning in confirmation hearings on his role in crafting policies that critics say contributed to the torture of detainees - to Ashcroft.
|Former US Attorney General John|
was criticised over the Patriot Act
During his four years in office Ashcroft was a lightning rod for criticism about how he applied parts of the Patriot Act.
Senator Dick Durbin of Illinois praised Gonzales's willingness to see some changes to the act. "It is a grand departure from your predecessor and I think it is the right spirit for us to address the Patriot Act."
Gonzales specifically proposed making changes to Section 215 - the measure of the law that deals with secret warrants for financial documents, library, medical and other records.
He said the law should be changed to ensure that only records relevant to a national security investigation can be requested.
He also said that people who receive a court order for records under that section should be allowed to consult a lawyer and challenge the order in court.
Mueller said it was important to renew all the expiring provisions to give the FBI the ability to share information and use all avenues to catch terrorists.
"In renewing these provisions scheduled to sunset at the end of this year, Congress will ensure that the FBI will continue to have the tools we need to combat the very real threat to America posed by terrorists and their supporters."
Mueller also called for an expanded ability for the FBI to obtain certain types of records without first asking a judge.