The Capitol is seen on a rainy morning in Washington, Friday, Dec. 28, 2018, during a partial government shutdown. Credit: J. Scott Applewhite | AP

Donald Trump threatened Friday to close the U.S.-Mexico border as a week-long partial government shutdown appeared likely to stretch into 2019 because of an impasse over funding for the president’s proposed border wall.

“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 said on Twitter.

Trump’s latest ultimatum comes a day after House Republicans said they didn’t plan any votes this week and as the president sought to shift blame to Democrats for a stalemate over funding for a wall that a majority of Americans don’t support, according to polls. It echoed a threat he made in November, when he said he’d close the border “for a long time” if Mexican authorities couldn’t quell attempts by large groups of migrants to cross into the U.S.

There was no sign of any progress toward a plan to fund nine government departments that closed after funding ran out Dec. 21. The Senate and House held brief sessions Thursday afternoon, and neither chamber took any votes.

Details of any potential closing of the 1,954-mile border with Mexico aren’t yet clear. Mexico is America’s third-largest trading partner in goods with $557.6 billion in two-way trade during 2017, according to the Office of the U.S. Trade Representative. Trade in services accounted for another $58 billion.

Trump said in another tweet that the U.S. “looses soooo [sic] much money on Trade with Mexico under NAFTA, over 75 Billion Dollars a year (not including Drug Money which would be many times that amount), that I would consider closing the Southern Border a ‘profit making operation.’ ”

The U.S. data report a $17.1 billion goods deficit with Canada in 2017, and a $71 billion goods deficit with Mexico. Both countries, however, reported substantially larger U.S. goods surpluses in the same relationship. In 2017, Canada reported a $97.7 billion surplus, and Mexico a $132.4 billion surplus.

Senators have been told they’ll vote only once there’s a deal backed by Democrats and by Trump, who is demanding $5 billion for a wall at the southern border, his central campaign promise. Democrats call such spending wasteful and ineffective. The standoff produced a fresh round of finger-pointing late on Thursday afternoon.

White House press secretary Sarah Sanders issued a statement outlining Trump’s demands that didn’t include the word “wall.” She said later there was no significance to that omission.

“The president has made clear that any bill to fund the government must adequately fund border security to stop the flow of illegal drugs, criminals, MS-13 gang members, child smugglers and human traffickers into our communities — and protect the American people,” she 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.”

The White House is flexible on the composition of the border wall Trump has demanded, one official said, noting that the president has used a variety of terms to describe it in recent days including slats, fence and barrier.

Sanders complained that Democrats haven’t responded to a compromise offer conveyed by Vice President Mike Pence late last week, and that the opposition party “decided to go home” while Trump stayed in Washington over Christmas to negotiate.

Underscoring the pressure Trump is facing from some in his own party, Representative Louie Gohmert of Texas said Friday on Fox News that the shutdown should continue “until Hell freezes over” if needed to secure funding for the barrier.

Senate Minority Leader Chuck Schumer rejected the offer from Pence, said his spokesman, Justin Goodman. The New York Democrat told Pence that Democrats won’t consider any offer without a public endorsement by Trump because the president has changed his position so often, said Goodman, who added the two sides remain far apart.

House Democrats answered in kind.

“Democrats have offered Republicans three options to reopen government that all include funding for strong, sensible, and effective border security – but not the president’s immoral, ineffective and expensive wall,” said Drew Hammill, a spokesman for Rep. Nancy Pelosi, D-California, who’s expected to become speaker of the House when Democrats take control of the chamber next week.

Earlier in the day, Trump said that most federal employees who aren’t receiving paychecks because of the government shutdown are Democrats.

“Do the Dems realize that most of the people not getting paid are Democrats?” Trump tweeted Thursday morning, prompting outrage from some in Congress. The president provided no evidence to support the claim, which he made only days after characterizing federal employees as supporters of the wall and the partial shutdown.

Virginia Sen. Mark Warner, the top Democrat on the chamber’s intelligence committee, called Trump’s tweet “outrageous,” adding on Twitter on Thursday that “federal employees don’t go to work wearing red or blue jerseys.”

The president, who returned to Washington early Thursday from a trip to visit U.S. troops in Iraq, tweeted about the standoff later, accusing Democrats of “OBSTRUCTION of the desperately needed Wall.”

Volatility returned to U.S. markets, with stocks bouncing back from the lows of the day after flirting with a bear market amid higher interest rates and the political turmoil in Washington. The S&P 500 and Dow Jones Industrial Average turned green in a late jump after trading negative for most of the day.

Federal workers will begin to lose money starting with Friday’s paycheck, according to National Treasury Employees Union President Tony Reardon. That check will reflect work through last Saturday, the day the shutdown began. That means Saturday shift workers, including many in Customs and Border Protection, won’t see pay for that day in their checks.

All workers in the nine departments and dozens of agencies with funding lapses will miss their Jan. 11 paycheck if the shutdown continues, he said in an interview.

“I’ve had members come to me saying they are returning holiday and Christmas presents they bought because they are worried about paying rent,” Reardon said. He said he was disappointed that Congress wasn’t in session working to reopen the government.

During the shutdown, Reardon said, “parks are being left open to illegal activity and vandalism, industrial complaints are going unanswered, the SEC isn’t investigating securities fraud and the IRS will have trouble implementing the largest legislative overhaul of the tax code in a generation.”

The Office of Personnel Management released form letters that furloughed workers could use to negotiate with creditors.

Sen. Pat Roberts, R-Kansas, who presided over his chamber’s brief session, said regarding government workers, “We respect them and we hope we can get this solved as quickly as possible.”

In addition, thousands of U.S. home sales are being held up because the shutdown has halted the issuance of new flood insurance policies. The Federal Emergency Management Administration stopped issuing new policies under the National Flood Insurance Program. FEMA, which oversees disaster response, is part of the Department of Homeland Security.

House members have been told they’ll get 24 hours’ notice if they need to travel back to Washington to vote on any deal.

Jim McGovern, the incoming Democratic chairman of the House Rules Committee, said if there isn’t a resolution by Jan. 3 when the new Congress is sworn in, the Democratic majority will vote on a stopgap spending measure to reopen the government agencies. He said Democratic leaders are discussing whether funding would last until Feb. 8 like the Senate-passed bill, for the full fiscal year through September, or until some other date.

Republicans say they’re still waiting for Democrats to respond to an offer from the White House last Saturday. The administration said it would accept $2.1 billion for border barriers along with a $400 million flexible fund for immigration priorities. Democrats dismissed the offer as hollow because Trump has said publicly he still wants $5 billion for a wall.

Congress is scheduled to return on Monday although no votes are scheduled, and lawmakers will be in recess on New Year’s Day. The current Congress ends at noon Jan. 3, when new members elected in November’s midterm election will take their oaths.

“I don’t see a scenario where the government opens back up before a new Congress is sworn in,” retiring Rep. Ryan Costello, R-Pennsylvania, said on MSNBC Thursday.

House Freedom Caucus Chairman Mark Meadows, R-North Carolina, sought to blame the shutdown on Schumer in a tweet Thursday urging the New York Democrat to accept $5 billion for a wall.

“The House passed it. The WH wants it. The Senate majority wants it. The one blocking an open government and a secure border: Chuck Schumer,” Meadows tweeted.

Bloomberg writer Alyza Sebenius contributed to this report.