Democrats’ efforts to be watchdogs for the federal government’s coronavirus response limped into motion Wednesday with the first meeting of a special committee created to examine the pandemic.

Yet the open briefing, held via videoconference, largely served to highlight the frustrations and limitations that lawmakers, especially Democrats, have encountered this spring as Congress has struggled to stake out its role in addressing the pandemic.

The proceeding did not feature any current administration officials as President Trump has balked at cooperating, calling the House a “bunch of Trump haters.” It took place nearly six weeks after the panel was first announced, it covered the familiar ground of testing and treatments with former federal health officials, and it at times devolved into partisan attacks — particularly from Republicans who compared the oversight effort to the impeachment of President Trump and slammed Democrats for not highlighting the virus’s origins in China.

“We should be looking at China, their role in this,” said Rep. Mark Green (R-Tenn.). “Because China lied, Americans died.”

Yet the oversight imperatives for the legislative branch are clear: Congress has already approved nearly $3 trillion in rescue funding — the largest emergency commitment of taxpayer resources outside of wartime the nation has ever seen — and there are ongoing questions about the administration’s ability to marshal the federal government to fight the virus amid its efforts to reopen the economy.

A Tuesday hearing of the Senate Health, Education, Labor and Pensions Committee — the first official proceeding featuring administration witnesses since mid-March — showed the power of the congressional spotlight.

Anthony S. Fauci, the top federal infectious-diseases expert, warned frankly about the dangers of an early reopening of the American economy, while Robert Redfield, director of the Centers for Disease Control and Prevention, said the country was “not out of the woods yet” — a sobering note amid Trump’s effort to quickly push parts of the country back toward normal footing.

But Congress stands to have relatively few opportunities to question those high-level officials in the coming months. White House guidelines issued last month strictly controlled the availability of officials involved in coronavirus work, with access to task force members such as Fauci and Redfield meted out by White House Chief of Staff Mark Meadows.

The White House denied a House Appropriations subcommittee’s request to summon Fauci to a hearing last week, indicating that the Democratic-controlled House is likely to face continued frustrations in conducting oversight that dates back more than a year — to the earliest days of their majority.

Still, the administration’s stonewalling is only part of the Democratic frustration; several lawmakers said this week that the nature of the pandemic has made it difficult for them to do more than apply political pressure on the administration and hope it translates into action.

Four coronavirus relief bills have so far shoveled taxpayer money at the problem, and a recent bill mandated that the administration submit a national testing plan by the end of the month, but the administration and its Republican allies have resisted stronger measures, such as nationalizing medical supply chains.

“The problem is not that their response is mishandled — the problem is they have no response,” said Sen. Chris Murphy (D-Conn.), who was among the Democrats who participated Tuesday in the Senate hearing. “They’re not running a national testing program. They’re not providing guidance to states on reopening plans. They’re not taking over the supply chain. So it’s kind of hard to do oversight over a response that doesn’t exist.”

The special House panel, chaired by Majority Whip James E. Clyburn (D-S.C.), has been billed as a measure to prevent waste, fraud and abuse in the distribution of the trillions of dollars in relief funds.

“This select committee was not established to cast blame on past failures, foreign or domestic, or to search for the virus’s origin [but] rather to pursue future success,” Clyburn said Wednesday, summarizing his charge at ensuring the relief effort is “effective, efficient and equitable.”

House Majority Leader Steny H. Hoyer (D-Md.) said he expected oversight activity to ratchet up as soon as next week, after the House adopts rules changes Friday allowing for remote work by committees — including official hearings and depositions by videoconference.

“That one big step is to make sure Congress can act,” he said.

A high-profile House hearing — one set to take place in person on Capitol Hill — is set for Thursday featuring Rick Bright, a former director of the federal Biomedical Advanced Research and Development Authority, who has publicly accused the administration of demoting him after he questioned the president’s efforts to promote unproven therapies such as an anti-malaria drug.

In his prepared testimony, Bright said the United States faces the “darkest winter in modern history” if it does not develop a more coordinated national response to the coronavirus before an expected resurgence later this year.

White House trade adviser Peter Navarro, who repeatedly warned colleagues about the coronavirus in memos earlier this year, has declined to testify before the House panel, the White House said Tuesday.

Meanwhile, the select committee’s early efforts — questioning the decisions of five publicly traded companies to accept aid money aimed at small businesses — have prompted partisan sparring. Republicans said that the companies are in fact eligible for the aid under the criteria lawmakers themselves created and that the letters sent last week by the panel’s Democrats amounted to unwarranted harassment.

Those claims got a boost when two Democratic House members joined a letter defending one of the companies, Universal Stainless and Alloy Products, as “exactly the type of company which the [Paycheck Protection Program] was created to assist.”

“Why on one hand would you tell people we want this lifeline out there to help keep people attached to their companies and keep people employed, and then turn around and target companies [who] are the very people we were trying to help?” said House Minority Whip Steve Scalise (La.), the panel’s top Republican.

Meanwhile, several bipartisan oversight organs set up as part of the $2 trillion Cares Act passed in March have yet to function. A five-member congressionally appointed oversight commission is awaiting the naming of its chairman, who must be jointly appointed by House Speaker Nancy Pelosi (D-Calif.) and Senate Majority Leader Mitch McConnell (R-Ky.).

Spokesmen for the two leaders declined to comment Wednesday on the status of the appointment. The four other members of the board issued a statement last week as they missed their first statutory deadline for issuing a report, saying they had “begun to review actions taken by the Treasury Department and the Federal Reserve” and “are working to fulfill our responsibilities, even in the absence of a staff, a budget, and a chairperson.”

Meanwhile, Trump’s nominee for special inspector general for pandemic recovery — Deputy White House Counsel Brian Miller — is awaiting confirmation by the Senate. The Senate Banking Committee advanced Miller’s nomination Tuesday; the Homeland Security and Governmental Affairs Committee is not set to take up the nomination until next week, making it unlikely he will be confirmed before next month.

Several congressional Democrats have been skeptical of Miller’s nomination, viewing him as too close to Trump to provide effective oversight, while his defenders point to a long record of nonpartisan service.

The grumblings have been, to some degree, bipartisan. Sen. Marco Rubio (R-Fla.), chairman of the Senate Small Business and Entrepreneurship Committee and co-author of the popular Paycheck Protection Program, said Wednesday that he has been frustrated trying to get senior officials from the federal Small Business Administration to appear before his panel.

“I think generally people in the executive branch don’t like to testify before Congress at large,” he said. “But we’ve got to do it. I don’t like going to the dentist, but I have to do it.”

But another Senate chairman said his committee was too busy working on legislation responding to the pandemic to hold oversight hearings.

“Not this month, not this month,” Senate Agriculture Committee Chairman Pat Roberts (R-Kan.) said Wednesday, when asked if he planned hearings on an American food supply chain that has been stressed by the pandemic.

Roberts pointed to the need for child nutrition legislation and ongoing talks with his House counterpart, Rep. Collin C. Peterson (D-Minn.), about possible farm provisions that could be included in the next rescue bill.

“We have a pretty good slate of things we have to do,” he said. “This has thrown us a big curveball.”

Erica Werner contributed to this report.