The White House and a number of federal agencies have started advanced preparations for a partial government shutdown, as President Trump and congressional Democrats appear unlikely to resolve their fight over a border wall before some government funding lapses at week’s end.

On Sunday, neither side appeared willing to budge from their negotiating positions over funding for Trump’s proposed wall along the border with Mexico.

“We’re going to do whatever is necessary to build the border wall,” White House senior adviser Stephen Miller said in an interview on CBS’s “Face The Nation.” Pressed on the prospect of a shutdown, Miller said, “If it comes to it, absolutely. This is a very fundamental issue.”

On NBC’s “Meet The Press,” Senate Minority Leader Charles E. Schumer (D-N.Y.) sounded equally dug into the Democrats’ position not to provide $5 billion for the wall.

“President Trump should understand — there are not the votes for the wall, in the House or the Senate. He is not going to get the wall in any form,” Schumer vowed.

The ratcheting up of the rhetoric from both sides suggests that finding even a short-term alternative to prevent some of the government from shutting down on Dec.22, three days before Christmas, is fading.

GOP congressional leaders are scrambling to find an alternative that could stave off a shutdown. But White House officials signaled to lawmakers Friday they would probably not support a one- or two-week stopgap measure. Some congressional Republicans support such a “continuing resolution,” but the White House rejection has dramatically increased the odds of a spending lapse.

“We could be headed down the road to nowhere,” said Senate Appropriations Chairman Richard C. Shelby (R-Ala.). “We’ll have a [continuing resolution] rather than a shutdown, I hope.”

Several budget experts believe a partial shutdown, which would impact agencies that manage law enforcement, homeland security, housing and other programs, could drag on for days, if not weeks. That is in part because Trump believes the final days of the existing Congress are his best chance to extract $5 billion in funds to partially build a wall along the Mexico border. In early January, Democrats take control of the House of Representatives, giving them more control over the process.

Multiple agencies and senior administration officials are preparing for the possibility that about a quarter of the government — and more than one-third of federal workers — could be left without funding during the holiday season.

The agencies themselves are providing scant information about what they will do if their funding lapses, and with the deadline days away, mass confusion remains about what would actually happen in a partial government shutdown.

The Statue of Liberty, for example, closed to thousands of visitors during a brief government funding lapse in January. National parks across the country stayed open, though without visitor centers and fees and with only minimal emergency staff.

National Park Service officials confirmed Friday that parks would stay open this time — but they declined to say whether the Statue of Liberty would again close.

“We are not going to speculate on any possible change in government operations,” Jerry Willis, a spokesman for the national park that encompasses the Statue of Liberty, wrote in a text message. He referred questions to the Park Service, where another spokesman wrote an identical message in response to an inquiry.

The lack of clarity on all fronts is seizing Washington just ahead of the Christmas holiday and as Democrats prepare to take control of the House, illustrating how jarring the transition in power could be next year.

Trump and some of his conservative allies on Capitol Hill view this as their last, best chance to deliver on the long-promised wall before they lose their grip on power, and they are reluctant to let the moment pass. But Democrats feel no pressure to give in to Trump’s demands weeks before they will assume control of the House.

At the same time, a number of Republicans are cringing at the possibility that their two years in control of Congress and the White House could end, shamefully, in a partial shutdown of the government they command. From the sidelines, rank-and-file Republicans are urging Trump and Democratic leaders to find a compromise between Trump’s demands for $5 billion for his border wall — even though he long claimed Mexico would pay for it — and Democrats’ insistence that they will spend no more than $1.3 billion on fencing.

“I’m sorry that we’re in this situation, because the American people deserve better from both sides,” said Rep. Tom Cole (R-Okla.). “Everybody that’s at the leadership level, and I include the president and the Democrats, are putting their perceived political interests ahead of a solution, and ahead of what’s good for the American people. And, you know, no wonder people don’t like this place.”

The standoff intensified following an outlandish televised meeting on Tuesday with Trump, Schumer and House Minority Leader Nancy Pelosi (D-Calif.). During their encounter, the president and his Democratic antagonists doubled down on their demands, and Trump declared he would be proud to shut down the government over border security.

There have not been any serious bipartisan talks since.

About 75 percent of the portion of the federal budget controlled by Congress has been funded through next September, including the Pentagon, Veterans Affairs and the Health and Human Services Department.

But the other 25 percent is operating on a short-term funding extension that runs out Friday at midnight. Unless a deal is reached, the departments of the Interior, Agriculture, State, Housing and Urban Development, Treasury, Commerce, and Homeland Security would lose funding. So would numerous smaller, independent agencies, including the Peace Corps, the Small Business Administration, the National Archives, the Environmental Protection Agency and the General Services Administration.

These agencies’ budgets were supposed to have been approved by last October.

About 800,000 of the 2.1 million federal employees across the country would be affected since their offices would lose funding to operate. About 40 percent of them would be sent home without pay, with the rest staying on the job because their work is considered essential to the functioning of the government, according to Capitol Hill aides and the contingency plans the agencies have filed with the Office of Management and Budget.

Federal agencies that will run out of funding were supposed to be notified Friday to begin activating their contingency plans. The plan provides the contours of what a partial shutdown would look like, even as the administration has issued little in the way of public guidance.

One reason for the confusion is that White House budget director Mick Mulvaney has given federal agencies much more leeway to remain open during a shutdown than his predecessors did. For example, he has directed national parks to remain open as they did during the brief shutdown last January, although visitor centers would be closed because their staffs would be sent home, and law enforcement would be minimal. Some agencies, such as the Environmental Protection Agency, have been directed to draw on reserve funding to keep employees at work instead of sending them home indefinitely without pay.

It is unclear if the White House will follow a similar approach this time, as multiple officials declined to comment. And Trump on Friday announced Mulvaney would be elevated to serve as acting chief of staff when the current chief, John F. Kelly, steps down at year’s end.

A partial government shutdown could portend bigger problems for Washington into 2019, as upcoming deadlines will repeatedly require Trump and Democrats to reach deals.

Capital Economics, a research firm, wrote in a note Friday that “the biggest downside risk (to the economy) is a prolonged federal government shutdown that morphs into a full-blown debt crisis sometime in the first half of next year.”

The White House and Congress will have to reach an agreement to raise or suspend the debt ceiling at some point next year, and Trump has not yet had to do this at a time when Democrats had any control over a chamber of Congress. Financial markets can become very unsettled when Washington dithers over raising the debt ceiling, and Trump had — before becoming president — suggested that the debt ceiling should not be raised.

Even a partial shutdown would cost taxpayers hundreds of millions of dollars in lost productivity, with federal employees likely to be paid for staying home. Other shutdown-related expenses would include revenue from fees and costs charged contractors for stop-work orders, for example.

In light of the potential for a shutdown, some Republicans have begun downplaying its impacts, suggesting that even if it did occur the public might hardly notice.

“Obviously we want to avoid a government shutdown, but if you look at what the real-world consequences would be, I think this shutdown would be different because we have funded most of the government, because President Trump has said he will make sure essential services continue,” said Rep. Richard Hudson (R-N.C.). “I don’t think the American people will feel an impact from this like they may have in the past. I also think that the most important thing is we’ve got to secure our Southern border because we have a national security crisis down there.

Employees who are called to work during a shutdown do get paid but not until the government reopens.

Employees who are furloughed are in theory not guaranteed to be paid once the government reopens. But after every previous shutdown, Congress has passed legislation mandating that they be paid.

The Department of Homeland Security would keep 85 percent of its 300,000 employees on the job, largely because they perform law and immigration enforcement roles that are considered essential during a shutdown. So airport security screeners, the Coast Guard, Border Patrol agents, and Immigration and Customs Enforcement agents would come to work, although their pay could be delayed.

But the vast majority of Housing and Urban Development’s 7,800 employees would be furloughed, as well as those at NASA.

So would the workforce of the Treasury Department, which includes the Internal Revenue Service. In the short term, the effect on the IRS would be minimal since tax season is four months away — but the agency is preparing to fully implement the complex tax legislation Congress passed last year.

The Food and Drug Administration would continue to respond to outbreaks of the flu or foodborne illnesses, but would send home more than 40 percent of its staff and would have to cease routine inspections. But most food inspection, for example of meat-processing plants, is done by the Agriculture Department, which would continue those operations in a shutdown.

About 3,600 forecasters for the National Weather Service would stay on the job, as would 5,000 Forest Service firefighters and 16,700 federal corrections officers.

But would-be homeowners would find delays as their applications for loans were backlogged by the closing of the Federal Housing Administration.

With many federal workers planning to be off the job anyway to use up their annual vacation time, the impact of a shutdown on them could be blunted.

Unions representing federal employees said Friday, though, that even a partial shutdown would cause significant disruptions to the operations of government.

J. David Cox, president of the American Federation of Government Employees, the largest federal employee union, said it was wrong to minimize a potential shutdown because it would not affect the entire government.

“Picking and choosing certain agencies to stay open and leaving others to close is missing the point,” he said in a statement. “The federal government and its agencies are interconnected, the services funded by taxpayers are rightfully expected to be delivered year-round.”