The number of sexual assaults brought to the attention of military authorities was 6,769 in 2017, up from 6,172 in 2016, according to the report from the Defense Department's sexual assault prevention and response office.

For the period under review, the proportion of women in the armed forces increased slightly, from 16% at the end of 2016 to 16.3% at the end of December 2017.

The number of reported assaults within the ranks of the Marines saw the sharpest increase (14.7%), while they rose 8.4% in the Army, 9.3% in the Navy and 9.2% in the Air Force.

"We will not rest until we eliminate this crime from our ranks," said Admiral Ann Burkhardt, director of the Pentagon's sexual assault prevention and response office.

"We consider this desire to report (sexual assault) as the result of 10 years of efforts to improve victim support, criminal investigations and military justice."

A single phone number has been set up for victims of sexual assault in the military, who can decide not to make their case public, even to their superiors. Only the prevention and response office is informed.