WASHINGTON >> U.S. military officials have sought to ward off congressional efforts to address child-on-child sexual assaults on bases, even as they disclose that the problem is larger than previously acknowledged.

Members of Congress expressed alarm and demanded answers after an Associated Press investigation revealed that reports of sexual violence among kids on U.S. military bases and at Pentagon-run schools are getting lost in a dead zone of justice that often leaves both victim and offender without help.

With at least three potential legislative fixes being drafted, military officials have had a clear message during briefings with lawmakers and their staffs: We can handle this on our own. It’s a strategy that began months ago, after the Pentagon received AP’s questions and well before officials understood the scope or severity of the problem.

In March, AP documented nearly 600 sex assault cases among children and teens on U.S. bases worldwide over a 10-year period. Army criminal investigators have now added another 86 investigations to the 223 they initially disclosed. The revision came after AP challenged data that suggested major installations in several states and overseas had no or only a few such sexual assault cases.

One Texas congressman has filed legislation that would direct the Pentagon to transfer cases to state authorities, who unlike the military or federal prosecutors have much more experience handling juvenile offenders. At least two Senate offices are drafting legislative language to address the problems that AP’s reporting revealed.

In response, officials from the service branches and the Pentagon school system lobbied for time to fix the problem themselves, according to interviews and records.

School system officials have told AP they were developing new rules for responding to the sexual violence. The Defense Department promised more broadly to take “appropriate actions” to help juveniles involved in sex assaults.

“I think they would like to make the corrections … because, simply, they can do it faster than Congress can,” Sen. Joni Ernst, an Iowa Republican who served in the Army National Guard and is a member of the Senate Armed Services Committee, said of her meeting with Pentagon school system officials.

Ernst said school officials did not offer specific steps they would take and that, while she supported internal reforms, she might still back legislation.

A staffer in another senator’s office said the military briefers thought they were getting the problem under control.

“They did not want any legislative action on this,” said the staffer, who was not authorized to speak publicly and did so on condition of anonymity. The staffer thought legislation would be needed.

Some military officials began discussing how to limit congressional involvement last fall, as AP was gathering records and data about child-on-child sexual assaults on bases. At that point, the Pentagon was not tracking the problem, but some military officials expected news coverage to generate attention from Congress.

AP’s investigation found that many reports were shelved by military criminal investigators, while other cases were unprosecuted by civilian authorities, who are responsible because military law doesn’t apply to service members’ families.

“I hope to be able to demonstrate that we are making progress on our own, and do not need any legislative assistance,” Col. William Smoot, the Army’s chief of criminal law, wrote in an October email to fellow Judge Advocate General lawyers. Smoot asked colleagues to relate how they were coordinating with civilian prosecutors so that the Army could “determine what, if any, changes should be made.”

Approached in person recently, Smoot referred a reporter to the Army’s press office, which later characterized the email as reflecting the Army’s desire to “coordinate its efforts with Congress.”

“Although the Army has sufficient authority to improve its response to juvenile misconduct cases,” a statement said, “the Army greatly respects Congress’ oversight role and will continue to work closely with Congress on this issue.”

Last month, the Army’s Criminal Investigation Command released data under a Freedom of Information Act request that showed it had undercounted the number of investigations its agents had conducted.

The additional cases the Army released showed that installations where the agency had reported zero incidents in fact did have investigations. Those included bases in Hawaii, Louisiana, Missouri, Alabama, Alaska, Oklahoma, South Korea and Germany.

Army Criminal Investigation Command spokesman Chris Grey wrote in an email that the agency “hand searched” cases that it had recorded as still “open,” some dating to 2007, and found that 86 had been closed. Investigators concluded the allegations were true in 83 percent of those cases, AP found.

The Army still has not disclosed the number of pending sexual assault investigations it has involving kids on base.

The lack of reliable tracking concerns Sen. Claire McCaskill, a Missouri Democrat and former prosecutor who also sits on the Senate Armed Services Committee. In an April 27 letter to Army Secretary Mark Esper, she wrote of the “strong possibility” that the military was not coordinating well with civilian authorities.

“I am sure you would agree that close coordination between the Army and local or federal law enforcement is critical to ensuring all cases of sexual assault on Army installations are addressed appropriately,” McCaskill wrote.