US President Donald Trump repeatedly threatened a government shutdown over funding for his proposed border wall in a budget row with top Democrats.
During a heated exchange with Nancy Pelosi and Chuck Schumer, Mr Trump said he would be "proud" to shut down the government over border security.
If lawmakers cannot agree on a federal budget, funding for some departments will run out at the end of next week.
Mr Trump has asked to include $5bn (£4bn) in the deal for border security.
But Senator Schumer and Congresswoman Pelosi said they had agreed to extend funding for the Department of Homeland Security at current levels of $1.3bn (£1bn) until 30 September 2019.
Mr Trump opened the Oval Office meeting calling it a "great honour" to have Mr Schumer and Mrs Pelosi present, in their first meeting since Democrats took control of the House of Representatives in the November mid-term elections.
But the meeting soon turned contentious as Mrs Pelosi and Mr Schumer argued that the Republican-controlled Congress could pass legislation before funding for some agencies was set to expire on 21 December.
The president contended that it could only pass if it met his demands for more funding for his proposed border wall along the US southern border.
"If we don't get what we want, one way or the other, whether it's through you, through military, through anything you want to call, I will shut down the government," Mr Trump said.
"And I am proud to shut down the government for border security. I will take the mantle. I will be the one to shut it down."
The clock is ticking...
Analysis by Anthony Zurcher, BBC Washington
Donald Trump opened his press event with Democratic leaders Nancy Pelosi and Chuck Schumer with a feel-good embrace of bipartisanship.
It didn't last long.
The two Democrats and the president sparred over funding for the Mr Trump's proposed border wall. It seemed for a moment as though they might agree on funding for "border security" - but that linguistic pirouette disappeared beneath an onslaught of acrimony.
The president wants his wall funding. He campaigned on it. He promised it. And even though Mexico isn't going to pay for it, he wants it now.
Democrats, on the other hand, are loath to give him this victory. What's more, they're intent on having the blame for any government shutdown directed solely at the president.
In the end Mr Trump gave the Democrats what they wanted. He said he would shut down the government if "we don't get what we want". He would be "proud" to do it.
Democrats will try to make the president regret those words. Mr Trump, on the other hand, thinks the public - or at least his base - is with him in this fight.
If neither side blinks, we'll know who is right in a few weeks.
In an official readout following the meeting, White House spokeswoman Sarah Sanders said the Democrats have "made clear they would rather keep the border open than the government open".
After the meeting, Democrat Chuck Schumer condemned Mr Trump's "temper tantrum" in the White House Oval Office.
Nancy Pelosi, who is expected to become Speaker of the House when Democrats take over the chamber next month, mocked Mr Trump at a later meeting with colleagues on Capitol Hill.
"I was trying to be the mom," she said, sources told US media. "It goes to show you: you get into a tinkle contest with a skunk, you get tinkle all over you."
She reportedly added that the president's insistence on a wall was "a manhood thing".
Hours before the meeting, Mr Trump tweeted that "the Military will build the remaining sections of the Wall".
But a defence department said later: "To date, there is no plan to build sections of the wall."
If the budget stalemate cannot be resolved, funding for about a quarter of government departments, including justice, agriculture and homeland security, will run out on 21 December.
The remaining parts of the federal government, including the defence department, have been funded until 2019.
Hundreds of thousands of government employees would be forced to stay home in the event of a shutdown.