WASHINGTON - President Donald Trump heaped pressure on Democrats Friday to yield in an acrimonious budget showdown that threatens to shut down the US government when money runs out at midnight - a year to the day after the Republican president took office.

The Senate’s top Democrat, Chuck Schumer, arrived at the White House in the early afternoon for 11th hour talks with Trump on averting a shutdown, but there were no obvious sign of a breakthrough.

“Shutdown coming?” Trump tweeted as the day began, seeming to revel in the chaotic, high-stakes brinksmanship unfolding on Capitol Hill.

The president put on hold plans to fly to Florida to celebrate the first anniversary of his inauguration at his Mar-a-Lago estate to remain in Washington for what could be a night of down-to-the-wire votes in the Senate.

Instead, he made calls to Democrats to try to win Senate passage of a funding extension that had been pushed through the House of Representatives on Thursday by a vote of 230 to 197, White House officials said.

“Democrats are needed if it is to pass in the Senate - but they want illegal immigration and weak borders,” Trump said on Twitter.

Republicans, who have a tenuous one-seat majority in the Senate, need as many as a dozen Democratic crossover votes to reach the 60 votes required.

Democrats, however, appeared determined to block the measure, insisting on a deal that would protect from deportation so-called “Dreamers” - the 700,000 immigrants who entered the country illegally as children.

The House measure, which would extend funding until February 16, reauthorizes for six years a health insurance program for poor children - a long-time Democratic objective - but not the Deferred Action on Childhood Arrivals program, known as DACA, that affects Dreamers.

White House officials insisted there was no urgency to fix DACA, which expires March 5.

“This is purely an attempt by the Senate Democrats led by Schumer - why we call it the ‘Schumer shutdown’ - to try and get a shutdown the president gets blamed for,” White House budget director Mick Mulvaney told reporters.

 Political risks

With mid-term congressional elections looming later this year, Republicans risk being blamed by voters if the government grinds to a halt over lack of funds.

A new Washington Post/ABC poll found that 48 percent of Americans blame Trump and the Republicans for a potential shutdown, and only 28 percent blame Democrats.

There have been four government shutdowns since 1990. In the last one in 2013, more than 800,000 government workers were put on temporary leave.

Essential functions like the military, law enforcement, the White House and Congress would continue working but with reduced staff. Some agencies would shut down altogether.

The Pentagon issued a guidance confirming that active duty military, including those in combat, would work without pay, as will essential civilians. But others in the massive bureaucracy will be sent home without pay.

“The Department will, of course, continue to prosecute the war in Afghanistan and ongoing operations against Al-Qaeda and Islamic State of Iraq and Syria, including preparation of forces for deployment into those conflicts,” said Patrick Shanahan, the Pentagon’s number two.

International ratings agency Fitch said a partial shutdown was unlikely to affect America’s AAA/stable rating for US sovereign debt.

 Shorter extension

Schumer said if agreement is not reached by Friday night, Democrats would support a shorter-term funding measure that would “give the president a few days to come to the table.”

But House Majority Leader Kevin McCarthy was quoted as telling reporters the chamber would adjourn as planned on Friday afternoon - all but guaranteeing a shutdown unless a last-minute deal is struck on the existing bill.

Republican Senate Majority Leader Mitch McConnell said the House bill provides for four weeks of funding, enough to allow talks to continue “without throwing the government into disarray for no reason.”

Schumer wants to “hold the entire country hostage,” McConnell said.

Negotiations with the White House on a bipartisan compromise on DACA blew up last week after Trump reportedly referred to African nations and Haiti as “shithole countries.”

 ‘Like a Sphinx’

Trump’s unpredictable Twitter outbursts and sudden changes of position also have bedeviled Republican leaders as they maneuver to cut a deal.

Schumer described Trump as “like a Sphinx on this issue,” a sentiment Republicans also appeared to share.

“Thinking people change their minds all the time. You do, I do, most Americans do when they test their assumptions against the arguments of others,” “We need to know where the president stands,” Senator John Kennedy, a Republican from Louisiana said Friday on CNN.

“Let’s suppose we reach an agreement with the Democrats, and I think we will - I want to know the president is going to sign it.”