"As the United States Court of Appeals for the Ninth Circuit noted in 2011, the [Veterans Administration] has acknowledged that an estimated 18 veterans complete suicide every day — over 6,500 every year," they wrote. "We lose more veterans to suicide every year than we do to hostile fire or enemy action, and by a huge margin."

The fiscal 2012 Defense Department spending bill, and the Veterans Affairs bill, each allowed $20 million for anti-suicide efforts. That language was also in the FY 2013 bills, and the House is expected to take up work on 2014 spending bills later this year.

Runyan said people who serve in the military need the "complete support" of Congress when they return home.

"As the number of suicides among U.S. military personnel continues to rise, it is imperative that we do everything we can to reach out and let them know about the resources that are available to them," he said. "One service member or veteran who takes their own life is one too many."

"Before this day is out, if it is like every other day, 18 more veterans will have taken their own lives," Holt said. "Congress has begun to take this crisis seriously over the past few years, but we must continue providing the funding and support necessary to help keep our soldiers and veterans alive."