A 33-year veteran of the US military, Lieutenant General Ann Dunwoody, on Monday became the first woman to be nominated to the highest rank in the US Army, four-star general.

"This is an historic occasion for the Department of Defense and I am proud to nominate Lt Gen Ann Dunwoody for a fourth star," Defense Secretary Robert Gates said in a statement.

Dunwoody's nomination has to be approved by the US Senate.

She would take over as commander of Army Materiel Command, a branch of the army that provides logistics support to tens of thousands of US soldiers stationed around the world.

Dunwoody was named deputy commanding general of Materiel Command only last week, following the retirement of Lieutenant General William Mortensen.

Army spokeswoman Lieutenant Colonel Anne Edgecomb told AFP the nomination of Dunwoody to the rank of four-star general was "important, considering that there are about 11 four-star generals in the army and we have a total force of 1,077,500 soldiers," of whom 14 percent are women.

Edgecomb was unable to say when the nomination might be approved by the Senate.

"It depends on what the Senate's schedule is," she said.