An Oval Office meeting between President Trump and Democratic leaders Sen. Chuck Schumer and Rep. Nancy Pelosi spiraled out of control over funding for the border wall Tuesday, devolving into what Schumer called a Trump "temper tantrum."

With a potential government shutdown looming less than two weeks away, Pelosi, the presumptive soon-to-be speaker of the House, told Mr. Trump, "you will not win" on the border wall. The president demanded border wall funding — and said he's not afraid the shut down the government over it. In fact, he said, he's proud to do so, and will take credit for it.

"I am proud to shut down the government for border security, Chuck," the president said. "So I will take the mantle. I will be the one to shut it down. I'm not gonna blame you for it. The last time you shut it down it didn't work. I will take the mantle of shutting down. And I'm gonna shut it down for border security."

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Mr. Trump is pushing for $5 billion for his border wall — Democrats don't want to give him much more than $1 billion. Government funding runs out Dec. 21, days before Christmas.

President Trump speaks with Senate Democratic Leader Chuck Schumer, D-New York, in the Oval Office of the White House in Washington on Tue., Dec. 11, 2018. Reuters

Mr. Trump began the meeting by welcoming Pelosi to the Oval Office, and noting he hopes Democrats can work with Republicans on passing criminal justice reform legislation. But that was the friendliest point of the meeting.

From there, the roughly 13 minutes of discussion White House reporters were allowed to see dissolved into Mr. Trump demanding border wall funding, and Schumer and Pelosi saying he won't get it.

The Democrats questioned whether airing their grievances on national television was the best way to handle their differences. But Mr. Trump insisted he wanted "transparency."

Vice President Mike Pence, meanwhile, looked on and said nothing.

U.S. House Speaker designate Nancy Pelosi (D-CA) speaks with Vice President Mike Pence and U.S. President Donald Trump as they meet with her and Senate Minority Leader Chuck Schumer (D-NY) in the Oval Office at the White House in Washington, U.S., December 11, 2018. Kevin Lamarque / REUTERS

Here's one exchange that's emblematic of how the entire meeting went:

PELOSI: Thank you for the opportunity to meet with you so that we can work together in a bipartisan way to meet the needs of the American people. I think the American people recognize that we must keep government open — that a shutdown is not worth anything. And that you should not have a Trump shutdown. TRUMP: A what, did you say? PELOSI: Trump shutdown. You have the White House. You have the Senate. You have the House of Representatives. You have the votes. You should pass it. TRUMP: No, we don't have the votes, Nancy. Because in the Senate we need 60 votes. PELOSI: No, but in the House. You can bring it up right now.

After the meeting, Schumer and Pelosi told reporters outside the White House that the shutdown will be Mr. Trump's responsibility, and Mr. Trump's alone.

"The president has the White House, he has the Senate, he has the House of Representatives, all in Republican control," Pelosi said. "He has the power to keep government open. Instead, he has admitted in this meeting that he will take responsibility, the Trump shutdown is something that can be avoided. The American people do not need at the time of economic uncertainty, people losing jobs, the market in the mood and the rest, the Trump shutdown is luxury that the American people cannot afford."

Despite all that, White House press secretary Sarah Sanders described the conversation as "constructive dialogue."

"President Trump had a constructive dialogue with Democrat Leaders Chuck Schumer and Nancy Pelosi," Sanders said in a statement after the meeting. "The president and the Democrat Leaders agreed to support the passage of historic criminal justice reform, and discussed significant progress with the farm bill. Major disagreement remains on the issue of border security and transparency. Walls work – where walls have been built, illegal crossings have dropped substantially. President Trump made clear that any government funding measure must include responsible border security, including a wall, to protect the American people from drugs, crime, terrorism, public health threats, and the severe straining of the social safety net."

There were warning signs the meeting might not go well.

Mr. Trump fired off a series of tweets Tuesday morning blasting Democrats and urging them to secure the border. Mr. Trump claimed Democrats "for strictly political reasons and because they have been pulled so far left, do NOT want Border Security."

"I look forward to my meeting with Chuck Schumer & Nancy Pelosi. In 2006, Democrats voted for a Wall, and they were right to do so. Today, they no longer want Border Security. They will fight it at all cost, and Nancy must get votes for Speaker. But the Wall will get built," the president tweeted.

Earlier this year when the president met with Schumer behind closed doors, he appeared to have reached a deal on protecting recipients of the Deferred Action for Childhood Arrivals (DACA) program, in exchange for border wall funding. Mr. Trump ultimately rejected that. The government shut down.

Arden Farhi contributed to this report.