WASHINGTON - Defense Secretary Chuck Hagel informed President Obama of the latest sexual-assault allegations against a military man who was assigned to prevent such crimes - the second involved in similar accusations - and the president made clear he wants that behavior stopped, officials said Wednesday.

Hagel spokesman George Little told reporters that Hagel's staff was working on a written directive that would spell out steps aimed at resolving a problem that has outraged lawmakers.

"The president has made very clear his expectations on this issue," Little said, adding that Hagel told Obama on Tuesday about the allegations facing an Army sergeant first class at Fort Hood, Texas. The sergeant is facing allegations involving three women, including that he may have arranged for one to have sex for money, according to a defense official.

The accused soldier, whose name has not been made public, was assigned as a coordinator of a battalion-level sexual-assault prevention program at Fort Hood. He has been suspended from all duties but has not been charged with any crime.

Little said Hagel and Obama saw the sexual-assault problem in the same light.

"They expect prevention measures at all times, and when prevention isn't achieved, then both expect accountability," Little said. He said those were the "core principles" of Hagel's approach to resolving the problem within the military.

The allegations at Fort Hood are only the latest in a string of cases. A defense official in Washington said it was not yet clear if one of the three women was forced into prostitution.

The official, who spoke on condition of anonymity because he was not authorized to speak publicly, said the sergeant was also being investigated for allegedly sexually assaulting one of the other women.

The case, along with another one involving an Air Force officer, highlights a problem that is drawing increased scrutiny in Congress. Lawmakers said it was time for Hagel to get tough with the military brass.

"To say this report is disturbing would be a gross understatement," said Sen. Kirsten Gillibrand (D., N.Y.).