"We were just informed last night (that) the National Nuclear Security Administration (NNSA) -- the group that handles and manages our nuclear stockpile -- that the carryover funding they've been using is about to run out," Republican congressman Mike Rogers told reporters.

"They will have to lay off 80 percent of their employees."

The federal government shutdown is set to head into a new week with no end in sight after the Senate failed for a 10th time on Thursday to pass the Republican bill to reopen the government.

It was not clear if Rogers was referring to temporary enforced leave during the shutdown, or permanent layoffs.

But he added: "These are not employees that you want to go home. They're managing and handling a very important strategic asset for us. They need to be at work and being paid."

The United States has a stockpile of 5,177 nuclear warheads, with about 1,770 deployed, according to the global security nonprofit Bulletin of the Atomic Scientists.

The NNSA is responsible for designing, manufacturing, servicing and securing the weapons. It has fewer than 2,000 federal employees who oversee some 60,000 contractors.

Energy Secretary Chris Wright told USA Today in an interview Thursday touching on the effects of the shutdown on the NNSA that "starting next week, we're going to have to let go tens of thousands...of workers that are critical to our national security."

The newspaper reported that staff at the agency had been told that furloughs -- or enforced leave without pay -- could begin as soon as Friday.

- Massive cuts -

Senators headed to their home states Thursday after their latest failed vote to end the shutdown that started on October 1 when the federal government ran out of Congress-approved funding.

If the standoff remains unresolved by the end of Tuesday next week it will have lasted 22 days -- making it the second-longest in history.

The record of 35 days came during a fight over border wall funding in President Donald Trump's first term in the White House.

Democrats have been urging Trump to get more involved in the current gridlock, asserting that only the president will be able to move Republicans in Congress from their policy of refusing to negotiate until the government has reopened.

Republicans leaders have been privately discouraging Trump's involvement, fearful that he will strike an unpalatable deal on expiring health care subsidies that is at the heart of Democratic demands.

The president is seeking to push through massive cuts to the federal bureaucracy during the shutdown.

White House budget chief Russ Vought said in an interview he wants to see "north of 10,000" jobs cut -- although a federal judge temporarily blocked shutdown-related layoffs, ruling that they were politically motivated and unlawful.

With 1.4 million federal workers either sent home without pay or working for nothing, Trump intervened to ensure military personnel received their checks on Wednesday, although doubts remain over future disbursements.

Republican Senate Majority Leader John Thune told MSNBC in an interview that aired Thursday he would guarantee Democrats a vote on extending health care subsidies in exchange for reopening the government.

"I've said, if you need a vote, we can guarantee you get a vote by a date certain," he said. "At some point Democrats have to take yes for an answer."