Senate Minority Leader Charles Schumer (L) (D-NY) looks on as House Minority Leader Nancy Pelosi (D-CA) speaks to reporters during a news conference at the U.S. Capitol.

Trump has pushed for $5 billion to build the physical barrier on the U.S.-Mexico border, calling it essential to cracking down on illegal immigration, an issue that he considers "a total winner" politically . Democrats and even some Republicans consider the wall not only inhumane but also ineffective. Trump had repeatedly said he would make Mexico pay for the wall.

As she will likely hold the House speaker's gavel next month after her party gained 40 seats in last month's midterms, Pelosi appears emboldened ahead of what could become the third shutdown of the year. The meeting Tuesday will help to decide which party will yield in perhaps the last major legislative scrum under unified Republican control of the White House and Congress.

Trump will meet with the Democratic congressional leaders at 11:30 a.m. Tuesday as they try to strike a deal to avoid a partial government shutdown when funding expires after Dec. 21. The biggest sticking point is whether to fund the president's proposed border wall, a top Trump campaign promise that Democrats have vowed not to give him.

When President Donald Trump faces Nancy Pelosi and Chuck Schumer on Tuesday, his favorite foils will carry a lot more leverage than they have held at any point in the nearly two years since the president took office.

For more than a year, Trump has shown willingness to let the government shut down in order to secure wall funding. Last month, he said he would be "totally willing" to do so. If spending talks crumble, funding will lapse for seven government agencies — including the Department of Homeland Security, which is crucial to enforcement of U.S. immigration policy.

At least two possible solutions have surfaced: approving a smaller chunk of money for border security, or extending current funding levels for up to a year and passing off the political battle to the next Congress.

"Republicans still control the House, the Senate, and the White House, and they have the power to keep government open. Our country cannot afford a Trump Shutdown, especially at this time of economic uncertainty," Pelosi and Schumer said in a joint statement Monday. "This holiday season, the president knows full well that his wall proposal does not have the votes to pass the House and Senate, and should not be an obstacle to a bipartisan agreement."

In a string of tweets Tuesday morning ahead of the meeting, Trump appeared to lower expectations for approving his desired border wall funding. He said "I look forward to my meeting" with Schumer and Pelosi but claimed the lawmakers "no longer want" border security. Democrats have repeatedly disputed that claim, as they passed an additional $1.6 billion for border security in last year's spending bill.

Trump claimed "the Wall will get built" even if Democrats do not approve the money. He contended that "people do not realize how much of the Wall, including really effective renovation, has already been built." While Congress has allocated money to build new fencing or replace existing structures on the border during Trump's administration, it has not constructed any of the "wall" prototypes that the president desires.

He claimed the military would "build the remaining sections of the Wall" if Democrats do not approve cash to construct it. It is unclear how that would happen, as Congress already passed a Defense Department spending bill without border wall funding. Trump sent troops to the U.S.-Mexico border earlier this year as he tried to stoke concerns about an approaching "caravan" of Central American migrants.

Trump tweet

Trump tweet

In a tweet last week that misspelled "border," Trump said "Nancy and Chuck must approve Boarder Security and the Wall!"

Trump tweet

Pelosi has drawn a line in the sand as she prepares to lead the House. Last week, the California Democrat said she would not approve border wall funding in exchange for legal protections for young immigrants brought to the U.S. illegally as children — a deal Democrats were reportedly open to earlier in the Trump administration. Pelosi called them "two different subjects."

Beyond the considerations of keeping the government open, Pelosi also has to deal with dynamics within her party as she tries to secure enough votes to become speaker next month. Some current and incoming House Democrats have agitated not to give Trump a cent for his immigration goals. The leaders of the current GOP-held House support $5 billion in border wall money.

As his party's Senate seats will dwindle to 47 from 49 next month, Schumer has shown more willingness to compromise with Trump than Pelosi has. He has supported a bipartisan deal to approve $1.6 billion in funding for border security fencing — but not a "wall" as Trump describes it. Lawmakers approved the same sum for border security in last year's spending bill.

Last month, Schumer accused Trump of throwing a "temper tantrum" over the wall and said "the president is the only person who holds the ultimate responsibility for a government shutdown."