WASHINGTON, D.C. — President Bush on Friday picked Marine Corps Gen. Peter Pace, a loyal member of Defense Secretary Donald Rumsfeld's inner circle, to be chairman of the Joint Chiefs of Staff, the nation's highest military post.

Pace's confirmation would make him the first Marine Corps officer to hold the post.

The promotion would cap a career that has been closely associated with the military policies of the Bush administration, from managing the war on terrorism to the invasion of Afghanistan and Iraq.

Pace, 59, already is a White House insider and a close confidant of Rumsfeld, who guided his selection. He has served as vice chairman of the Joint Chiefs since 2001, working directly with Rumsfeld and providing him with advice on all major military decisions.

"To the American people, 'Marine' is shorthand for 'can do,' and I'm counting on Pete Pace to bring the Marine spirit to these new responsibilities," Bush said at a White House ceremony also attended by Vice President Dick Cheney, Rumsfeld and outgoing Deputy Defense Secretary Paul Wolfowitz.

The chairman of the Joint Chiefs of Staff — a post that requires Senate confirmation — is the principal military adviser to the president, the defense secretary and the White House's National Security Council.

The son of an Italian immigrant, the Brooklyn-born Pace "knows the job well," Bush said, adding that the position is a "huge task even in peacetime." The president praised Pace for his "wisdom and determination" and said he would help guide the reshaping of the armed forces "so we can defeat today's enemies while preparing ourselves for military challenges we will face as this new century unfolds."

As vice chairman, Pace already wields considerable insider clout in debates at the highest levels of government. He regularly provides advice to the White House National Security Council and to the Nuclear Weapons Council, a joint panel of the departments of defense and energy that oversees the nation's nuclear arsenal.

He also heads a powerful Pentagon panel that draws up requirements for new weapons systems and helps run another panel that shepherds them from the laboratory to the battlefield.

Air Force Gen. Richard Myers, the current JCS chairman, is due to retire at the end of September after four years as chairman and 19 months as vice chairman.

At the same ceremony, Bush nominated Adm. Edmund Giambastiani, 56, as vice chairman of the Joint Chiefs. Giambastiani is chief of the U.S. Joint Forces Command, based in Norfolk, and was previously Rumsfeld's military assistant.

The president had difficulty pronouncing Giambastiani's name and, after three halting attempts, said to the audience's laughter: "He shall be known as Admiral G."

Sen. Carl Levin, Mich., senior Democrat on the Senate Armed Services Committee, called Pace and Giambastiani "outstanding choices," adding that "they are both experienced and thoughtful military officers."

Pace will immediately face a slate of hot-button national security issues: the insurgency in Iraq, the ongoing U.S. presence in Afghanistan; the global war on terrorism; modernization of the U.S. armed forces; management of military recruitment shortfalls; and defending another round of contentious military base closings later this year.

A 1967 graduate of the U.S. Naval Academy with an MBA from George Washington University, Pace saw combat in Vietnam and rapidly rose through the ranks. In 1996 he served as director of operations for the Joint Chiefs of Staff where he was involved in all aspects of planning and deployment of U.S. forces.

In 2000 he was commander of the Miami-based U.S. Southern Command, responsible for planning all U.S. military activities in Latin America south of Mexico and in the waters adjacent to Central and South America and the Caribbean. Southern Command's area of responsibility encompasses 32 countries and 14.5 million square miles.