Watch: US President Donald Trump in spectacular fight with top Democrats in front of press

US President Donald Trump openly fought with the top two Democratic lawmakers in the Oval Office about government funding, as disagreements over a US-Mexico border wall prompted him to threaten a government shutdown.

In a remarkable public argument, the likes of which is seldom seen before cameras, Trump brawled with US Senate Democratic Leader Chuck Schumer and House Democratic Leader Nancy Pelosi about funding a wall they see as ineffective and wasteful.

"If we don't get what we want, one way or the other - whether it's through you, through a military, through anything you want to call - I will shut down the government," Trump said as the heated argument drew to a crescendo.

"I am proud to shut down the government for border security, Chuck, because the people of this country don't want criminals and people that have lots of problems and drugs pouring into our country," he said before reporters left their ringside seats.

Vice President Mike Pence sat beside Trump, silent and stone-faced.

While Trump's fellow Republicans control the House of Representatives and Senate until next month, Democratic support is needed to pass spending legislation.

If the impasse cannot be resolved by December 21, about one-quarter of the US federal government would be immediately left without funding.

Ironically, Trump would be shuttering the very agency in charge of border security - the Department of Homeland Security. Other federal agencies that also would face closures include the departments of State, Commerce and Agriculture, and visitors would not be allowed into federal parks.

Trump has asked Congress for $US5 billion for border security, while Schumer and Pelosi have offered to extend funding at current levels, around $US1.3 billion.

When he ran for president in 2016, Trump vowed that a US-Mexico border wall would be built and that Mexico would pay the full cost, an idea the Mexican government never embraced.

Democrats want to bolster border security by fixing fences and using high-tech equipment to detect illegal crossings.

After the meeting, White House spokeswoman Sarah Sanders said it was a "constructive dialogue" and Trump was "grateful" cameras captured him fighting to protect the border.

Back on Capitol Hill, Schumer accused Trump of throwing a tantrum, while Pelosi told reporters she had asked Trump to pray about resolving the dispute, recounting the biblical story of King Solomon asking God for wisdom.

The harsh words continued during a closed meeting of House Democrats, with Pelosi saying Trump's fixation with building a wall was "like a manhood thing for him. As if manhood could ever be associated with him," . according to an aide in the room.

Pelosi told reporters that later in the day that she and Trump spoke by telephone, and the president said he was reviewing the offer made by Democrats during the White House meeting.

This rocky meeting was the first Trump held with Pelosi and Schumer since Democrats won control of the House in November 6 elections, possibly foreshadowing battles to come next year.

The fight kicked off when Pelosi told Trump that Americans did not want to see a "Trump shutdown," touching a nerve.

"If I needed the votes for the wall in the House, I would have them in one session, it would be done," Trump bragged.

"Well then - go do it, go do it," Pelosi shot back.

Senior White House staff watched the melee from the edges of the room.

Reuters