WASHINGTON — Democrats on the Senate Armed Services Committee told Gen. Robert Neller on Tuesday that they were skeptical of his promises to change the Marine Corps culture in the wake of a nude photo-sharing scandal.

Neller, the Marine Corps commandant, called on victims of the “Marines United” Facebook page to come forward to assist in the ongoing probe by the Naval Criminal Investigative Service and said new social media policies were set to be released by the service.

Acting Navy Secretary Sean Stackley, who also testified Tuesday to the committee, called the social media activity a “cancer.”

Neller told lawmakers that he will travel with Marine Corps Sgt. Maj. Ronald Green to Camp Lejeune, N.C., this week and speak directly to troops about the social media scandal.

Sen. Kirsten Gillibrand, D-N.Y., her voice seeming to crack with emotion, said the response “rings hollow” after the service has failed for years to significantly reduce high rates of sexual assault. Sen. Jeanne Shaheen, D-N.H., said the high level of sexual assaults in the Marines relative to the other services is likely connected to the photo-sharing problem.

“This committee has heard those kinds of statements since I’ve been on the committee and, I believe, much longer,” Shaheen said. “Why should we believe it’s going to be different this time than it’s been in the past?”

Neller acknowledged the doubts and the services’ struggle with sexual assault but vowed that this effort to stamp out misogynist culture will be different.

“I don’t have a good answer for you,” Neller said. “I know you’ve heard it before but we are going to have change the way we see ourselves.”

The Marine Corps is on Capitol Hill this week to brief lawmakers on the investigation into the Facebook page, where photos — sometimes nude — of identified female servicemembers along with misogynistic comments were posted. Copycat pages have popped up and the Army has begun looking into whether soldiers are implicated.

“We all have to commit to getting rid of this perversion from our culture,” Neller told senators.

He is expected to meet Thursday with the House Armed Services Committee.

The service and Defense Secretary Jim Mattis condemned the activity in statements last week and said a task force has been created to look into policy changes to combat the problem.

The service estimates about 500 Marines were involved in the photo sharing out of the Facebook page’s 30,000 members and at least some of them are likely officers, Neller said, though the service did not provide a breakdown Tuesday.

“I’m not going to speculate on what the level of officer involvement is … it is highly unlikely that this is just enlisted,” he said.

Less than 10 victims were identified and some male Marines have come forward with information but Neller said those numbers are too small and he encouraged others to speak up.

“They have my word the leadership will not take retribution toward them,” Neller said.

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