Standing alone for a brief Washington news conference, Gonzales called his time as the top U.S. justice official "an incredible journey."

"We live in the greatest country in the world and I have lived the American dream," the son of Mexican immigrants said. "Even my worst days as attorney general have been better than my father’s best days."

Democrats and even some Republicans had been calling for Gonzales to step down for months amid allegations he lied during a Congressional investigation into the political firings of nine U.S. attorneys last year.

Gonzales did not address the allegations during his brief news conference Monday, nor did he address charges the Justice Department violated civil rights in its sweeping terrorism investigation.

The resignation is seen as a further blow to lame duck President Bush, who steadfastly defended his longtime friend.

Bush was expected to name a replacement for Gonzales later Monday. His last day in office will be Sept. 17.