US President Donald Trump, House Minority Leader Nancy Pelosi and Senate Minority Leader Chuck Schumer clashed over funding for the border wall, an explosive Oval Office encounter that ended with Trump declaring he'd be proud to shut down the government to get what he wants.

The stunning public spat, during which Schumer accused the President of throwing a "temper tantrum," ended with no resolution and appeared to increase the chances of a partial government shutdown at the end of next week.

The three leaders pointed fingers, raised their voices and interrupted each other repeatedly as they fought over policy and politics.

Schumer lectured Trump that "Elections have consequences, Mr President."


Trump claimed that, because she is working to nail down the votes to become speaker, "Nancy's in a siutation where it's not easy for her to talk right now".

Pelosi answered: "Please don't characterise the strength that I bring to this meeting."

It was the first encounter among the three leaders in more than a year, and if it offered a taste of politics in Washington next year when Democrats control the House, the Capitol is in for a rough ride.

Pelosi repeatedly asked the President to take the encounter off-camera but it continued for nearly 20 rancorous minutes before Trump ejected the media.

But even in private, it appeared little was resolved, although Pelosi told reporters later that she began with a prayer about King Solomon.

Pelosi and Schumer both implored Trump not to shutdown the government. Trump initially said he didn't want a shutdown either but in the end announced that he did.

"I am proud to shut down the government for border security, Chuck," Trump said, insisting the public doesn't want criminals and others coming into the country. "I'm going to shut it down for border security."

"We believe you shouldn't shut it down," Schumer said.


"I am proud to shut down the government for border security, Chuck," Trump said.

Nancy Pelosi and Chuck Schumer speak to members of the media outside the West Wing of the White House. Photo / AP
Nancy Pelosi and Chuck Schumer speak to members of the media outside the West Wing of the White House. Photo / AP

Trump wants US$5 billion for the wall in 2019 while Democrats are offering only US$1.3 billion - a gulf that showed no signs of getting bridged.

The meeting occurred several hours after House Republicans dug in on their demand for US$5 billion in support of Trump's stance.

"Our position is the President's position," House Speaker Paul Ryan told reporters at a news conference. "We share the President's goal. ... We need to secure the border."

Funding for the Homeland Security Department and a number of other agencies dries up on December 21 unless Congress and Trump act first.

Senate Majority Leader Mitch McConnell urged Democrats to accomodate Trump's wall demands, warning lawmakers either needed to cooperate or "prepare for a very, very long month".

"For the nation's sake, I hope that my Democratic friends are prepared to have a serious discussion and reach an accommodation with the President on funding for border security," he said in a speech on the Senate floor.

There were two brief government shutdowns earlier this year, one of them provoked by Senate Democrats over immigration.

The US$1.3 billion would extend current funding levels contained in the spending bill for the Homeland Security Department - which Democrats want to maintain at existing levels if no new deal can be reached.

If there is no agreement by the end of next week, funding will run out for the Homeland Security Department and other agencies including the Justice, Interior and Agriculture departments. Those agencies, making up about 25 per cent of the federal government, are operating on a short-term spending bill Congress passed last week to move the shutdown deadline. The rest of the federal government, including the Pentagon, has already been funded through the 2019 budget year.

Earlier, Trump expressed his desire for border wall funding across five meandering tweets.

He touted his administration's efforts to deter illegal border crossings, praising Border Patrol officers and the military for doing a "FANTASTIC job" and claiming that "Our Southern Border is now Secure and will remain that way."

Yet Trump argued that the "Great Wall" he repeatedly promised on the campaign trail would be "a far easier & less expensive solution," and he accused Democrats of resisting his plans "for strictly political reasons".

Trump also threatened that if Democrats don't provide enough votes to build the wall, "the Military will build the remaining sections." He did not elaborate on how that would be funded. Trump had long promised that Mexico would pay for the wall but it's now on US taxpayers to foot the bill.

Democrats have argued that if there is a partial shutdown, Trump and Republicans will be to blame because of their political pursuit of a wall that doesn't meet genuine national security goals.