WASHINGTON, D.C.- A bill that would extend Agent Orange benefits to thousands of ailing U.S. Navy veterans hit a last-second snag in the U.S. Senate.

The so-called “Blue Water Navy Bill” died in the U.S. Senate when Sen. Mike Enzi, a Wyoming Republican, objected, expressing concerns about the bill’s cost, according to Stars and Stripes.

The bill would make tens of thousands ailing veterans eligible for disability compensation and health care from the VA.

Those veterans served on ships that patrolled territorial waters off the Vietnam coast during the war and were exposed to Agent Orange and other herbicides.

Initially, Utah Sen. Mike Lee, a Republican, opposed the bill because he wanted to wait for a 2019 scientific study on the issue, but he withdrew the objection.

The Senate plans to adjourn for this session by week’s end, which means the bill is likely doomed until next year. The House has already voted unanimously for passage.

Montana Sens. Jon Tester and Steve Daines vowed Monday to keep up the fight for the Blue Water Bill and plan to hold a news conference Tuesday to draw more national attention to the issue.

Tester is the ranking Democrat on the Senate Veterans Affairs Committee.

“These are the folks who came back from war and there was nobody waiting for them at the airport. Nobody. And now we’re going to deny them the benefit that they have earned because they were exposed to Agent Orange, and there is no doubt they were exposed to Agent Orange,” Tester said in a floor speech.

Daines, a Republican, said, “Our veterans deserve much better. It is unacceptable that a technicality in the law and a disfunctional federal bureaucracy has resulted in the prolonged suffering of thousands of our nation’s heroes.”

The U.S. House passed nearly identical legislation earlier this fall – but in the Senate – an individual lawmakers can put a hold on most any bill.

Tester and VA Committee Chairman and Georgia Sen. Jonny Isakson promise to keep working on a possible compromise to see if they can save the bill before the current lame duck session of Congress adjourns at the end of this week