US President George Bush has nominated Gen Peter Pace as the next chairman of the joint chiefs of staff - America's top military post.
Gen Pace said the challenges ahead were formidable
The 59-year-old nominee is currently staff deputy chairman and would be the first marine appointed to the position.
Gen Richard Myers is due to retire in September after four years in the job.
It is now up to the Senate to consider the nomination of Gen Pace, who played a key role in shaping strategy for the US-led "war on terror".
The chairman of the joints chiefs of staff is America's highest-ranking soldier and principal military adviser to the president and defence secretary.
"The first thing America needs to know about Pete Pace is that he is a marine," Mr Bush said.
"To the American people, the marine is shorthand for can-do, and I'm counting on Pete Pace to bring the marine spirit to these new responsibilities."
The president said Gen Pace would help with the task of transforming the US armed forces to "defeat today's enemies while preparing ourselves for military challenges" of tomorrow.
If appointed, Gen Pace will be faced with the considerable task of implementing the modernisation programme in a context of US budget deficits.
"I know the challenges ahead are formidable," said Gen Pace, who has been the joint chiefs deputy chairman since 2001.