WASHINGTON – The partial government shutdown that began last week appears all but certain to continue into the new year.

Officially, both the House and the Senate each are scheduled to reconvene Monday, New Year's Eve.

But those are expected to be little more than pro forma sessions based on the sharply articulated positions both sides have taken on funding of a wall on the U.S.-Mexico border: President Donald Trump and most congressional Republicans demand the funding as part of a government spending bill, while most congressional Democrats oppose it.

The House and Senate returned to work Thursday for the first time since Saturday but quickly adjourned after scheduling no votes, signaling once again that little, if any, progress has been made toward resolving the budget impasse that has shut down a quarter of the federal government.

Appearing on FOX News Channel’s Fox & Friends on Friday morning, Mick Mulvaney, Trump’s incoming chief of staff, predicts the stalemate won’t be resolved until Democrats come back for the new Congress and likely select Democratic House Leader Nancy Pelosi, D-Calif., as their new speaker.

“We fully expect that until (Nancy Pelosi) is elected speaker and has locked that vote up, we don’t expect to hear from the Democrats again,” he said. Pelosi is expected to be elected speaker Jan. 3.

Trump would remain in Washington through New Years Day, Mulvaney said.

While Trump tweeted about "Democratic OBSTRUCTION" Thursday, White House Spokeswoman Sarah Sanders admonished Democrats for leaving town, though most Republicans, who control both chambers of Congress, were not in Washington either.

"The President and his team stayed in Washington over Christmas hoping to negotiate a deal that would stop the dangerous crisis on the border, protect American communities, and re-open the government. The Democrats decided to go home," she said in a statement. "The only rational conclusion is that the Democrat party is openly choosing to keep our government closed to protect illegal immigrants rather than the American people."

Sanders said the president "does not want the government to remain shut down, but he will not sign a proposal that does not first prioritize our county’s safety and security.”

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On Friday, Trump continued tweeting his attacks against Democrats. He threatened Friday to close the U.S. border with Mexico if Democrats continue to oppose funding for his proposed wall, but he did not spell out how he would carry out such a policy or what it would mean.

"We will be forced to close the Southern Border entirely if the Obstructionist Democrats do not give us the money to finish the Wall & also change the ridiculous immigration laws that our Country is saddled with," Trump tweeted.

Trump has made the threat before but has not offered details. Illegal crossings are at the heart of his dispute with congressional Democrats over funding for a proposed all along the U.S.-Mexico border.

It's also uncertain how closing the border would affect migration. Many people seeking to enter the United States claim political asylum, and the government is required to consider those request regardless of border closures.

Although the president is blaming Democrats for closing the government, Trump said he was willing to own the shutdown earlier this month during a combative meeting in the Oval Office with Pelosi and Senate Democratic Leader Charles Schumer, D-N.Y.

“If we don’t get what we want … we will shut down the government,” Trump said during the Dec, 11 exchange which played out in front of news cameras and reporters.

On Thursday, Drew Hammill, a spokesman for Pelosi, disputed the president's characterization of Democrats as obstructionists.

“Democrats have offered Republicans three options to re-open government that all include funding for strong, sensible, and effective border security – but not the President's immoral, ineffective and expensive wall," he said in a statement.

Pelosi is likely to become speaker after Democrats take control of the House of Representatives in January.

Contributing: David Jackson.

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