The number of sexual and other misconduct allegations targeting senior Pentagon officials has increased over the past several years, a new report says.

A report conducted by the Pentagon’s inspector general has found that "there was a 13 percent increase in complaints alleging misconduct by senior officials.”

“The most common allegations involved personal misconduct, including improper relationships, improper personnel actions, misuse of government resources, and travel violations,” according to the report.

The number of substantiated allegations increased from 26 to 37 percent for investigations conducted by both the Department of Defense inspectors general and inspectors general of the military services, defense agencies and military commands, the report found.

"In the category of personal misconduct, there has been a steady trend in substantiated allegations of improper relationships and sexual misconduct," it said.

The report concluded that "ensuring ethical conduct" will be one of the top 10 "management and performance" challenges for the Defense Department next year.

It said the department "continues to be confronted with high-profile misconduct cases including an Army major general misusing his government travel card...”

The report also found that on the issue of sexual assault, ensuring proper investigation of claims and ensuring victims do not suffer retaliation "remains a continuing challenge," and "reports of sexual assault continue to rise."

Meanwhile, US lawmakers called for the armed services to modernize treatment of sexual harassment and assault allegations.

Senator Kirsten Gillibrand criticized the Pentagon back in September for not doing more to combat rising rates of sexual assault in the military. He denounced the military “to see that sexual assault in our military is still as pervasive as ever.”

Gillibrand said that “levels of civilian survivors remain high, overall prosecution rates of military sexual assault cases remain flat, and my office received no retaliation cases from the DoD (Department of Defense) despite six out of 10 survivors reporting that they had been retaliated against last year.”