While the House Veterans Affairs Committee seeks reforms regarding toxic exposure illnesses, the Veterans Affairs department sought a delay on Wednesday.

Fifteen bills to help veterans suffering from illnesses believed to be caused by overseas exposure to toxic air or materials await action in Congress.

The legislation has been spurred by veterans' efforts to obtain disability benefits often getting blocked by the lack of scientific evidence connecting illnesses to specific exposures.

The committee met on Wednesday to streamline the process with a planned omnibus package of legislation in the House.

The effort is led in the House by Rep. Mark Takano, D-Calif., and Rep. Mike Bost, R-Ill. A similar reform bill in the Senate is led by Sen. John Tester, D-Mont., and Sen. Jerry Moran, R-Kan.

"We cannot continue to tackle this topic one exposure at a time or one disability at a time," Takano said at Wednesday's hearing. "We're committed to advancing comprehensive legislation this Congress."

Bills already introduced range from offering advice on navigating the VA bureaucracy to an expansion of health care to veterans exposed to Agent Orange, radiation and burn pits.

Burn pits have been a common 21st method of waste disposal by U.S. troops in the Middle East, notably in Iraq and Afghanistan.

Open-air combustion led to the hazards to potential "short- and long-term health effects, especially for those who were exposed for long periods or those more prone to illness such as individuals with pre-existing asthma or other lung or heart conditions," a 2016 VA statement said.

Nearly 800,000 of the 2.5 million Global War on Terrorism veterans have filed claims regarding respiratory issues.

On Wednesday, VA secretary for policy and oversight Ronald Burke asked the House committee to delay Congressional action until the VA finishes an internal review of toxic exposure and submits a report to Congress within 180 days.

Committee members, though, stressed the need to quickly move a comprehensive bill to law.

"My responses today are not designed to frustrate the committee," Burke said. "The department is committed to working with Congress and addressing this in a more holistic, faster, more accurate approach that is desperately needed."