US Secretary of Defense Donald Rumsfeld resigned Wednesday, a day after an American electorate, frustrated with the progress of the war in Iraq, elected a Democratic leadership in the House of Representatives and at least a half-share of the Senate. President George W. Bush announced Rumsfeld's resignation at a press conference Wednesday, and said he had asked Robert Gates, the former director of the Central Intelligence Agency, to replace him. "Now, after a series of thoughtful conversations, Secretary Rumsfeld and I agreed that the timing is right for new leadership at the Pentagon," Bush said. "Our military has experienced an enormous amount of change and reform during the last five years while fighting the war on terror; one of the most consequential wars in our nation's history." Asked whether his announcement signaled a new direction in the war that has claimed the lives of more than 2,800 US troops, Bush said, "Well, there's certainly going to be new leadership at the Pentagon." Bush described Gates, who will face Senate confirmation, as a man with "more than 25 years of national security experience and a stellar reputation as an effective leader with sound judgment." Gates served under Bush's father, president George H.W. Bush, and worked closely with former secretary of state James Baker and former national security adviser Brent Scowcroft. But American Jewish leaders said Wednesday he did not express the same hesitancies about the US-Israel relationship that his superiors at the time maintained. Bush lavished praise on Rumsfeld, who has spent six stormy years at his post. The president disclosed he met with Gates last Sunday, two days before the elections. Last week, as he campaigned to save the Republican majority, Bush declared that Rumsfeld would remain at the Pentagon through the end of his term. Rumsfeld, 74, was in his second tour of duty as defense chief. He first held the job a generation ago, when he was appointed by president Gerald Ford. Whatever confidence Bush retained in Rumsfeld, his support in Congress had eroded significantly. Rep. Nancy Pelosi, (D-California), who is likely to be voted the next speaker of the House, said at her first post-election news conference that Bush should replace the top civilian leadership at the Pentagon. And Senate Majority Leader Bill Frist, who had intervened in the past to shore up Rumsfeld, issued a statement saying, "Washington must now work together in a bipartisan way - Republicans and Democrats - to outline the path to success in Iraq." Rumsfeld had also increasingly been criticized by those in and around the nation's military. Last weekend, the Army Times called either for Rumsfeld to resign or Bush to fire him. The Pentagon offered no date for Rumsfeld's departure. Gates, 63, has served as the president of Texas A&M University since August 2002, and as the interim dean of its George Bush School of Government and Public Service from 1999 to 2001. The school is home to the presidential library of Bush's father. Gates is a close friend of the Bush family, and particularly the first president Bush. He served as deputy national security adviser from 1989 to 1991 and then as CIA director during the first Iraq war, from 1991 until 1993. Gates joined the CIA in 1966 and is the only agency employee to rise from an entry level job to the seventh-floor director's office. He served in the intelligence community for more than a quarter century, under six presidents. Bush had considered Gates for jobs before, including in 2005 when he was searching for a candidate to be the nation's first national intelligence director. Bush said Wednesday that he is looking forward to hearing findings of a bipartisan Iraq Study Group, co-chaired by Baker and former congressman Lee Hamilton. The committee is analyzing the current situation and is expected to offer recommendations. Matthew E. Berger is a reporter for Congressional Quarterly. AP contributed to this report.