Inside a contentious meeting in the Situation Room at the White House on Wednesday, the usually reserved Vice President Pence leveled a sharp accusation at Senate Minority Leader Charles E. Schumer: He never bothered to respond to an offer to reopen the government that Pence made days earlier.

Schumer was prepared with a response. Turning to President Trump, the New York Democrat reminded him that he said this week he wouldn’t accept less than the $5.6 billion in wall funding that was approved by House Republicans late last year — far more than the $2.5 billion Pence was proposing.

 “Didn’t you, Mr. President?” Schumer pressed.

The president, with his arms folded, smiled and nodded, according to two people familiar with the meeting who requested anonymity to discuss the private discussions.

The meeting moved on and little progress was made toward ending a shutdown that will soon enter its third week.

The episode inside the Situation Room — a similar gathering will occur Friday when congressional leaders return to the White House — illustrated the negotiating perils that have bedeviled lawmakers when dealing with the mercurial president. 

In Trump, congressional Democrats and Republicans have found a principal who often changes his mind on a whim, whose messages to Capitol Hill can be mixed and who undercuts his own vice president and advisers in high-stakes negotiations with little hesitation.

But despite Trump’s unpredictability, lawmakers are wary of negotiating with any of his aides because they believe only Trump speaks for Trump — a lesson that has been reinforced in recent weeks.

As the partial government shutdown continued on Jan. 3, senators discussed what it will take to reopen the government. (Rhonda Colvin/The Washington Post)

Republican senators had come away from a mid-December lunch with Pence believing that Trump would sign a short-term government funding bill without the amount of wall money the president had demanded and soon passed a bill to avert a government shutdown. Then Trump said he opposed the legislation.

And without a consistent message from the president, Trump’s aides sometimes also offer conflicting versions of what he will accept.

While Pence and Mick Mulvaney, the acting White House chief of staff, were relaying to Democrats shortly after the partial shutdown began on Dec. 22 the $2.5 billion wall funding proposal — a senior administrative official was holding a briefing call with reporters stating that the president would accept no less than $5 billion.

A senior White House official said the differing positions made sense. “You don’t say publicly what you are trying to get privately,” they said.

Even GOP lawmakers, who have generally stood behind the president’s insistence on a border wall are gently urging Trump to provide a bit more clarity on what he actually wants. 

“I think the president has been trying to say all along that he wants a border security system that’s in place and he doesn’t feel like it was responded to,” said Sen. Mike Rounds (R-S.D.). “But I also think the president has to be very clear with regard to what he will accept.” 

The Wednesday briefing with congressional leaders began with Trump complaining about nominees being held up in the Senate — a process for which he has publicly blamed Schumer — before he turned it over to Homeland Security Secretary Kirstjen Nielsen, who was piped in by video from California.

The goal of the White House, which was facing accusations it wasn’t doing enough to end the shutdown, was to force Democrats to listen to a lengthy presentation on how bad, from the administration’s view, the situation was at the border, according to a senior administration official.

Nielsen began reciting administration talking points before she was quickly interrupted by Pelosi and Schumer, who accused her of misconstruing facts and overstating a “crisis,” White House officials said. 

“We came to negotiate,” Pelosi said.

There’s distrust on both sides. Democratic aides on Capitol Hill say their bosses are wary of being used as a prop by Trump and they viewed the Situation Room briefing as a stunt. White House officials said Democrats are so determined to oppose Trump that they are not interested in hearing the administration’s argument. 

There was loud crosstalk between the participants in Wednesday’s meeting. Schumer repeatedly asked the president why he wouldn’t sign a bill keeping much of the government open while conversations continued on the wall. “We would look foolish,” Trump told Schumer. 

Pelosi said several times there would be no money for Trump’s border wall. 

Pence, who is often quiet and deferential to Trump in meetings, spoke frequently, according to Sen. Richard J. Durbin (D-Ill.), who was in the Situation Room. So did Mulvaney, the president’s acting chief of staff. Both Pelosi and Schumer dislike Mulvaney, according to people familiar with their opinion of the former House member from South Carolina, and his comments didn’t help the negotiations move forward.

Mulvaney, who has also served as the administration’s budget chief, complained that the funding legislation in the Democratic proposal would provide more in foreign aid than the White House requested, according to Durbin. The Democrats in the room told Mulvaney that part of the bill was written by Sen. Lindsey O. Graham and he should talk to the South Carolina Republican about his concerns. 

Graham did not respond to a request for comment.

Meeting participants said Trump was open to some of the arguments made by Democrats.

Durbin said he discussed security challenges at the border and pointed out that only 17 percent of vehicles at ports of entry get scanned for narcotics — even though that’s how the vast majority of illicit drugs enter the United States.

“Well all of a sudden, the president says, ‘well, let’s put more money in there!’ And everyone says, ‘let’s put more money in there!’” Durbin recalled Thursday. “And I said, ‘now, that’s border security. And it’s bipartisan border security.’”

But its unclear whether any money for these scans will be added to any deal. Democrats said that when negotiating with Trump, verbal promises made during meetings often don’t come to fruition.

Trump also proclaimed that he is an expert on drones during the briefing, baffling lawmakers, Durbin said. At one point, Trump told Pelosi she should support a wall because she was a “good Catholic,” according to people familiar with the exchange.

The president also went off on seemingly unrelated topics, encouraging Schumer to read a letter sent to him by Kim Jong Un, as first reported by CNN, and then pulled it from his pocket, according to a person familiar with the meeting.

Lawmakers have grown frustrated that the shutdown has gone on with no end in sight. There were little actual negotiations on Wednesday and senior Republicans warned that the shutdown could drag on for months while saying Trump has to be the chief negotiator for the GOP. 

“In the end, it’s gotta be him,” said Senate Majority Whip John Thune (R-S.D.), the new No. 2 in Senate Republican leadership who also attended the briefing. “It can’t be the vice president, it can’t be members of his staff.” 

Thune is scheduled to return to the White House on Friday and even though he said the briefing this week was helpful, he did not sound optimistic progress would be made.

He said he’s keeping his expectations “low.”