WASHINGTON • A marine has become the first woman to complete the notoriously rigorous training course for United States infantry officers.

Many women serve as officers in the US Marines and other branches of America's armed forces but the woman, who has not been identified publicly at her own request, is the first to finish the 13-week infantry officer training course.

"I am proud of this officer and those in her class," Marine Corps commandant Robert Neller said on Monday.

"Marines expect and rightfully deserve competent and capable leaders, and these (Infantry Officer Course) graduates met every training requirement as they prepare for the next challenge of leading infantry marines; ultimately, in combat," General Neller added.

As an infantry officer, the woman, a lieutenant, will be assigned to lead a platoon of around 40 marines.

A total of 131 marines had started the infantry officer training course in July and 88 graduated on Monday, the Marine Corps said.

Three dozen women Marine Corps officers had previously signed up for the infantry training programme but failed to finish, according to the Marine Corps Times.

On its Twitter feed, the Marine Corps released a video showing the woman taking part in exercises in the mountains alongside male infantry officer candidates.

Women make up about 15 per cent of the nearly 1.4 million active duty troops in the US armed forces.

Former president Barack Obama opened up all military positions to women, including combat units, in March last year.

Women were previously technically barred from combat, but thousands of American servicewomen saw fighting in Afghanistan and Iraq nonetheless.

The Marines have been seen as the branch of the US military that has been the least accepting of women in combat roles and the infantry plays a special role in the lore of the corps.

AGENCE FRANCE-PRESSE