WASHINGTON — President Trump will not commit to signing legislation that would avoid a partial government shutdown on Saturday, his press secretary said, further roiling a chaotic debate that is splintering the Republican Party.

“At this moment, the President does not want to go further without border security, which includes steel slats or a wall. The President is continuing to weigh his options,” White House press secretary Sarah Sanders said Thursday in a statement.

The tumultuous turn of events has seen Trump reverse himself numerous times in recent days on the issue, first demanding $5 billion from Congress for a wall along the Mexico border, then declaring the military would pay for it, only to insist that the money come from Democrats next year.

As talks appeared to break down Thursday, senior Republicans in Congress even appeared unsure of what Trump actually wanted before he would sign legislation. The breakdown has prompted a hastily arranged meeting between Trump and House Republicans at noon Thursday.

The Senate unanimously passed a spending bill Wednesday night that would fund many federal agencies through February 8, following days of acrimony after Democrats refused to advance any new funding for a wall along the Mexico border.

House Republican leaders had hoped to advance an identical measure on Thursday morning, but they were met with an insurrection from some of their most conservative members and a blizzard of negative coverage from right-wing media outlets. That led Speaker of the House Paul Ryan, R-Wis., to cancel a press conference and head to the White House for a meeting with Trump over how to proceed.

Last week, Trump told Democrats he would be “proud” to shut down the government if they refused to give him $5 billion for the construction of a wall along the Mexico border. Democrats held firm and prevented such a bill from advancing in Congress, leading Republican leaders to backtrack and instead pursue a short-term spending bill that would avoid a shutdown and delay further debate until February.

Trump appeared to signal he was on board with backing down, writing in a series of Twitter posts Thursday morning that he would continue to press Democrats for wall funding next year and also claiming that he had taken other steps to make the border “tight.”

A number of federal agencies, including those that govern homeland security, law enforcement, transportation, and the Treasury Department, are set to run out of money after midnight Friday.

“I think the next few days could get complicated real fast,” said Rep. Carlos Curbelo, R-Fla.

If Congress doesn’t appropriate new money by Friday night, much of the operations at these agencies would halt, and thousands of federal workers and contractors around the country would be sent home without pay.

House lawmakers had hoped to pass the spending bill by Thursday so they could leave town, but prospects for that dimmed quickly amid the confusion over Trump’s position and whether enough Republicans were on board. Republican leaders will likely need to rely on support from dozens of Democrats in order to prevent a partial shutdown before the Christmas break.

“I think our focus is tomorrow and we’ll see if the votes are there to pass it,” said Rep. Mo Brooks, R-Ala., who attended a Republican caucus meeting on Thursday.

House Speaker Ryan stepped out of the caucus meeting to take a call from Trump, according to two congressional aides. Moments later, Trump tweeted: “When I begrudgingly signed the Omnibus Bill, I was promised the Wall and Border Security by leadership. Would be done by end of year (NOW). It didn’t happen! We foolishly fight for Border Security for other countries – but not for our beloved U.S.A. Not good!”

This seemed to be a sharp departure from his comments earlier in the day, which mentioned fighting with Democrats on the issue next year.

He has never said concretely whether he would vote for the short-term bill to keep the government open. Adding to the confusion, Ryan and the House Republican leadership unexpectedly canceled a previously scheduled news conference with reporters.

Earlier this week, Sanders said Trump wanted to keep the government open and was looking at other ways to finance the wall’s construction that wouldn’t require congressional approval. This was a big shift from his position last week, which was that Congress must give him $5 billion for the wall or he would shut many other government operations down.

But the backpedaling this week from Sanders and others led to a torrent of criticism from conservative media outlets and members of the House Freedom Caucus, who urged Trump to hold the line, saying that prospects for a wall will only worsen next year when Democrats take control of the House of Representatives.

Rep. Mark Meadows, R-N.C., who has urged Trump to veto any spending bill and force a debate over the wall, even if it leads to a shutdown, pleaded with colleagues to oppose the spending bill.

“We have to fight now or America will never believe we’ll fight,” Meadows told the closed-door Republican caucus.

Many lawmakers, particularly those who lost elections last month, have left Washington and aren’t expected to come back. That makes it harder for congressional leaders to rally the votes they need for any measures.

The construction of a wall along the Mexico border was one of Trump’s top campaign promises in 2016, and he vowed that he would somehow make Mexico pay for it all. Since he won the election, he has demanded the money come from Congress, seeking between $1.6 billion and $5 billion. At one point, he even insisted Democrats give him $25 billion fo r the wall.

In his Twitter posts early Thursday, he claimed his initiatives to move more agents along the Mexican border had made it “tight” and said he would not support infrastructure legislation next year unless Democrats eventually agree to finance the construction of a wall.

“Remember the Caravans?” Trump wrote on Twitter. “Well, they didn’t get through and none are forming or on their way. Border is tight. Fake News silent!”

The government’s Department of Homeland Security painted a much different picture of the situation just a few weeks ago. It reported that the number of people arrested or detained along the Mexico border reached a new high for the Trump presidency in November, as arrests of juveniles and parents with children continued to rise. U.S. Customs and Border Protection detained 25,172 members of “family units” in November, the highest number ever recorded.

Last week, Trump said terrorists were crossing the U.S. border and he also offered the unfounded claim that people with contagious diseases were entering the country. Incoming House Speaker Nancy Pelosi, D-Calif., and Senate Minority Leader Chuck Schumer, D-N.Y., met with Trump at the White House and managed to get Trump to say he would take responsibility if the government shut down. This upset many Republicans, who had wanted to blame Democrats for any impasse.

Trump had demanded $5 billion from Congress to pay for construction of a wall along the border, but Democrats – fresh off wins in the November midterm elections – refused. Republican congressional leaders backed down and instead are seeking to advance legislation that funds a number of government agencies through early February.

That bill passed the Senate unanimously on Wednesday night. House Republican leaders huddled Thursday morning, as passage in their chamber is seen as more complicated.

“It was presented as a fait accompli” that Trump will sign the bill, Rep. Chris Collins, R-N.Y., said of the meeting.

But Rep. Paul Gosar, R-Ariz., argued for a presidential veto.

“I hope the president vetoes anything we send that’s a cop-out. … The time to fight is now. I mean this is stupid,” Gosar said.

In another Twitter post on Thursday morning, Trump tried to make clear that he would insist on wall money next year even if he didn’t obtain any during the final days of 2018.

“The Democrats, who know Steel Slats (Wall) are necessary for Border Security, are putting politics over Country,” Trump wrote. “What they are just beginning to realize is that I will not sign any of their legislation, including infrastructure, unless it has perfect Border Security. U.S.A. WINS!”

Trump is planning to go to Florida on Friday afternoon for more than two weeks, and a partial government shutdown could have drawn complaints from lawmakers and the public if he was seen as vacationing in the sunshine.

Earlier this year, Congress and the White House passed measures that fund most government operations, such as the military, through September. But a number of spending bills were left incomplete, and funding for those programs expires at midnight Friday. That’s why there has been a rush to try to reach a solution this week.

On Tuesday, Sanders said Trump had asked each Cabinet secretary to see whether there’s extra money that could be used to pay for the wall’s construction. On Wednesday, Trump wrote in a Twitter post that the wall would be built by the military, though neither the White House nor the military has explained how that would happen. But on Thursday, Trump was back to insisting that funding come from Congress.

The Washington Post’s Mike DeBonis and John Wagner contributed to this report.

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