Speaking to reporters shortly after Trump's appearance in the Rose Garden, Pelosi and Schumer said they were taken aback by Trump's behaviour.
"To watch what happened in the White House would make your jaw drop," Schumer said.
Pelosi said Democrats had been prepared to deliver a signature accomplishment to Trump at a time when the nation's roads, bridges, airports and other infrastructure are ailing.
"For some reason, maybe it was lack of confidence on his part ... he just took a pass, and it just makes me wonder why he did," Pelosi said.
"In any event, I pray for the President of the United States, and I pray for the United States of America."
Trump was visibly angry when he arrived in the Cabinet room about 15 minutes late to meet with Pelosi and Schumer, according to people familiar with what transpired.
Trump did not shake hands or sit down, and after accusing Pelosi of saying something "terrible", he headed out without allowing time for a response.
Democtratic Senator Debbie Stabenow, who was there to take part in the meeting, said that after directing his anger toward Pelosi, he "said it was over, that he wasn't going to do infrastructure or anything else until [investigations] were over".
In the Rose Garden, Trump delivered his remarks from a podium with a sign reading, "NO Collusion, NO Obstruction," and that displayed statistics about the Mueller investigation, such as the number of subpoenas issued and witnesses called.
White House aides also distributed fliers with the statistics on them.
Calling the Mueller investigation "a one-sided, horrible thing", Trump lashed out at Democrats, investigators and the assembled journalists.
"This whole thing was a take-down attempt at the President of the United States - and honestly, you ought to be ashamed of yourselves for the way you report it so dishonestly," he told reporters.
Not mentioned by Trump were the indictments against 34 people, including six former Trump aides or confidants, as well as 26 Russians, that resulted from Mueller's nearly two-year probe.
A growing number of rank-and-file Democrats have called for the launch of an impeachment inquiry against Trump as frustrations build over the Administration's stonewalling of congressional probes.
But during Wednesday's meeting of House Democrats, most of the chairmen who addressed the caucus focused on recent successes in court battles to force the Administration to comply with subpoenas and counselled the more measured course advocated by Pelosi, according to multiple people in the room.
The meeting "reflected where most of this caucus is at", said Republican Dean Phillips.
"Have faith in the courts and have faith in process, and impeachment only if absolutely necessary."
Addressing reporters afterward, Pelosi said Democrats had "a very productive meeting", and she called for staying the course on investigations.
"We do believe that it's important to follow the facts," she said.
"We believe that no one is above the law, including the President of the United States. And we believe the President of the United States is engaged in a coverup."
In remarks to fellow Democrats during the meeting, Pelosi, according to multiple members, showed no sign of moving away from her approach.
"Stay the course," said Sean Patrick Maloney, summarising Pelosi's remarks.
During the meeting, House Financial Services chairwoman Maxine Waters was the only one of the chairmen to call for moving forward with impeachment proceedings, a stance consistent with her past advocacy for seeking to remove Trump.
"I never change my mind," she told reporters afterward.
While other chairmen said they were outraged by Trump's conduct, several offered reasons to follow Pelosi's lead. House Oversight and Reform Committee chairman Elijah Cummings, for instance, warned that some freshmen lawmakers in swing districts could lose races if Democrats are too aggressive in pursuing impeachment.
Ahead of the meeting, Trump aimed a barrage of early-morning tweets at House Democrats questioning their priorities as they prepared to discuss investigations into the administration amid the growing calls for impeachment proceedings.
In his tweets, Trump claimed that Democrats are "getting ZERO work done in Congress" and are instead focused on what he called a continuation of a "Witch Hunt" into whether he sought to obstruct special counsel Robert Mueller's investigation into Russian interference in the 2016 presidential election.
"PRESIDENTIAL HARASSMENT!" Trump wrote in the fourth of his tweets that began before 6am.
The President's Twitter rant came about three hours before the Democratic caucus meeting called by Pelosi.
Democrats have become increasingly frustrated with the Administration's refusal to co-operate with congressional requests for documents and testimony. That included the White House's refusal to allow former counsel Donald McGahn to testify at a hearing Tuesday about key aspects of Mueller's report.
During the meeting, most lawmakers appeared to side with Pelosi, according to people in the room. Even some of those who had advocated opening an impeachment inquiry sounded more measured as they left the meeting.
Jamie Raskin, who spoke up forcefully for an impeachment inquiry in a private leadership meeting Monday, declined to say after the meeting whether such an inquiry should now be launched.
"I just think we need to have a conversation about all the constitutional means that are available to us, and we're having that conversation," Raskin said.
One of the most vocal proponents of an impeachment inquiry, David Cicilline, rose during the meeting and spoke about the need for the House to ensure that "no one is above the law", making the case that impeachment proceedings would elevate the seriousness of the House's response to Trump.
"People understand the gravity of this moment," Cicilline said afterward.
"There was a very candid, respectful discussion about the best way to proceed. I think everyone recognises that this isn't just about Donald J. Trump, but it's about protecting the rule of law in this country and the implications it has for the future of our democracy."
Pelosi called the caucus-wide huddle amid increased pressure from some of her members to begin an impeachment inquiry. Monday night, a band of frustrated House Judiciary Committee members - including powerful chairman Jerrold Nadler - confronted Pelosi on her no-impeachment position and encouraged her to green-light an inquiry.
Pelosi refused, arguing that the caucus is not behind the move and that it would impede other committees in pursuing their investigations.
Pro-impeachment members, however, argue that an impeachment inquiry will enable investigators to more quickly secure documents and witness testimony that the White House has blocked at every turn. Since Monday, about 25 lawmakers have gone public to call for an inquiry to begin.
To ease the pressure and the tension, Pelosi had privately signaled that she will green-light more aggressive investigative measures, according to several lawmakers.
Pelosi, these lawmakers say, is also talking about so-called "inherent contempt" in a real way. That includes potentially tweaking House rules to allow chairmen to slap steep fines on Trump officials who ignore subpoenas.
Since taking control of the House in January, Democrats have passed several legislative measures, including bills on health care and ethics reform, that have not been taken up in the Republican-led Senate.
Prospects for an infrastructure deal seemed to dim even before Wednesday's aborted meeting.
In a letter to Pelosi and Schumer on Tuesday night, Trump wrote that it is his "strong view" that Congress should pass the trade deal his Administration negotiated with Canada and Mexico before turning its full attention to infrastructure.
The White House has stepped up pressure on Congress to pass the US-Mexico-Canada Agreement by the summer amid continuing Democratic concerns about parts of the deal.
During an appearance on Fox News on Wednesday morning, White House press secretary Sarah Sanders accused Democrats of "dragging their feet" on the trade deal and chastised them for talking about impeachment.
"Hopefully they're going to have a come-to-Jesus moment where they realise what a terrible idea this is," Sanders said ahead of the Democratic caucus meeting.
In his morning tweets, Trump continued to question why Democrats were interested in hearing the testimony from his aides and others who were interviewed as part of Mueller's investigation.
Mueller's report concluded that the Russian Government interfered in the 2016 presidential election "in sweeping and systematic fashion".
The report did not find sufficient evidence to bring charges of criminal conspiracy with Russia against Trump or anyone associated with his campaign. It did not offer a conclusion on whether Trump obstructed justice.
Barr later concluded that there was not sufficient evidence for obstruction of justice, but House Democrats are continuing to pursue that issue.
"After two years of an expensive and comprehensive Witch Hunt, the Democrats don't like the result and they want a DO OVER," Trump said in one of his morning tweets. "In other words, the Witch Hunt continues!"
Later Wednesday morning, Trump returned to Twitter to justify blocking the testimony of McGahn, his former White House counsel, to the Judiciary Committee.
"He (Jerry Nadler) wants a show," Trump said of the panel's chairman. "He wants to use Mr. McGahn as a prop to spend three hours claiming that Mr. Trump tried to obstruct the Mueller investigation. YET MR. MUELLER WASN'T OBSTRUCTED IN ANY WAY, HIS COPIOUS REPORT WAS RELEASED FOR ALL TO SEE, & THERE WAS NO COLLUSION."
