Obama, who also announced his other nominees for top national security posts today, cited the necessity of continuity as the United States fights wars in Afghanistan and Iraq as his rationale for asking Gates to stay.
In a statement, Gates said he is "deeply honored" that the president-elect asked him to continue serving.
"Mindful that we are engaged in two wars and face other serious challenges at home and around the world, and with a profound sense of personal responsibility to and for our men and women in uniform and their families, I must do my duty -- as they do theirs," Gates said in his statement. "How could I do otherwise?
"Serving in this position for nearly two years -- and especially the opportunity to lead our brave and dedicated soldiers, sailors, airmen, Marines and defense civilians -- has been the most gratifying experience of my life. I am honored to continue to serve them and our country, and I will be honored to serve President-elect Obama," Gates said.
Obama also announced his intent to nominate the following people to serve in his administration:
-- New York Sen. Hillary Rodham Clinton to be secretary of state;
-- Retired Marine Corps Gen. James L. Jones Jr. to be national security advisor;
-- Eric H. Holder to be attorney general;
-- Arizona Gov. Janet Napolitano to be secretary of homeland security; and
-- Susan Rice to hold Cabinet rank as U.S. ambassador to the United Nations.
Gates will not have to go through the Senate confirmation process. President George W. Bush nominated Gates as defense secretary in November 2006. The Senate approved the nomination, and he was sworn into office in December 2006 to succeed Donald H. Rumsfeld. Gates will be the first Cabinet officer to continue serving in an administration from a different political party.
Clinton has represented New York since her election in 2000 and has served on the Senate Armed Services Committee. She served as the chairwoman of the Task Force on National Health Care Reform in 1993. She has supported military action in Afghanistan, and has opposed recent actions in Iraq. In the Senate, she sponsored legislation to increase the size of the Army and has consistently worked to help military families. If confirmed, she will replace Secretary of State Condoleezza Rice.
Jones retired in 2007 after serving as NATO's supreme allied commander for Europe and commander of U.S. European Command. Before that assignment, he was the Marine Corps commandant. Jones received his commission through Georgetown University in Washington in 1967 and served in Vietnam. He received the Silver Star for his actions there. As NATO commander, he led the expansion of the International Security Assistance Force in Afghanistan. As national security advisor, he will help to coordinate all aspects of U.S. power in the war on terror. He is currently chairman of the Atlantic Council of the United States. If approved, he would replace Stephen Hadley.
Holder served as deputy attorney general in the Clinton administration. He also has served as a judge, a prosecutor and as a front-line lawyer in the Justice Department. A native New Yorker, Holder received his law degree from Columbia University. If confirmed, he would succeed Michael Mukasey.
If confirmed, Napolitano would be responsible for the Coast Guard as part of her portfolio as homeland security secretary. A lawyer, she served as Arizona's attorney general before being elected as governor in 2002. Napolitano would replace Michael B. Chertoff.
Rice served on the National Security Council in the Clinton administration as assistant secretary of state for African affairs. She will replace Zalmay Khalilzad in the U.N. post.