Embattled U.S. Attorney General Alberto Gonzales announced his resignation Monday in a brief statement at the Justice Department.
"Yesterday I met with President Bush and informed him of my decision to conclude my government services as Attorney General of the United States effective September 17."
He did not take questions from reporters.
Bush will likely nominate Homeland Security Secretary Michael Chertoff to the position, senior administration officials said.
Chertoff has headed Homeland Security since 2005. He served as a federal appellate court judge, a federal prosecutor and as special counsel for a Senate committee investigating President Clinton's involvement in the Whitewater land development.
Solicitor General Paul Clement will serve as acting attorney general, the White House press office said.
President Bush is expected to make a statement about Gonzales at 11:50 a.m. from his ranch in Crawford, Texas, where he has been vacationing, but will not announce a replacement, two senior administration officials said.
Late Update: Hold off on the Chertoff speculation, CNN's Suzanne Malveaux now told.