House Speaker Paul D. Ryan insisted on Thursday that there was “no evidence of collusion” between the president or his campaign and Russia, as Justice Department officials sought to placate Republicans challenging the credibility of their investigation.

Ryan’s public exoneration of the president and his campaign capped a frenetic 24 hours in which he voiced support for the FBI and the Justice Department, was attacked by the president’s supporters, and wrested a new concession from law enforcement officials.

Ryan is retiring at the end of the year, but as leader of the House Republicans, he has found himself refereeing the acrimonious standoff between GOP lawmakers and the Justice Department over access to classified information and documents relevant to the investigation of Russian interference in the 2016 presidential election and whether anyone in the Trump campaign coordinated with the Kremlin to influence its outcome. For the most part, Ryan has sided with his fellow Republicans on that dispute, and has previously denied any collusion between Trump associates and Russia. He did so again — emphatically — on Thursday.

House Intelligence Committee Ranking Democrat Adam B. Schiff told reporters on May 24 that there is still no evidence of a “spy” in the Trump campaign. (The Washington Post)

“Let’s just make that really clear: There’s no evidence of collusion. This is about Russia and what they did, and making sure they don’t do it again,” Ryan (R-Wis.) told reporters, in comments excoriating law enforcement agencies for not being more forthcoming with records that lawmakers had requested until Ryan intervened.

“It shouldn’t take a speaker of the House to have to get involved every one of these times to get the Department of Justice or any other department to comply with congressional oversight requests,” Ryan continued.

“The sooner the Department of Justice complies with all of our document requests, which are legitimate document requests, the better this is going to be for everybody,” he said. “Had they complied with these document requests earlier when we made them, we probably could have spared the country all of this drama.”

Ryan added to that drama with his comments over the past two days, which bookended an unusual late-night statement from the Justice Department offering a new classified briefing to senior lawmakers about the origins of the FBI’s Russia probe.

On Wednesday, Ryan said he agreed with initial assessments that the FBI did nothing improper when it began investigating Russian campaign interference in 2016, disputing President Trump’s assertion that federal law enforcement planted a spy inside his campaign. In doing so, Ryan endorsed comments made days prior by Rep. Trey Gowdy (R-S.C.), who was among the first to break with Trump over the controversy the president calls “Spygate.” Sen. Richard Burr (R-N.C.), chairman of the Senate Intelligence Committee, said Wednesday that he, too, supports Gowdy’s take on the evidence.

But it was Ryan who took the brunt of the blowback, particularly from the GOP faction on Capitol Hill that has been leading the charge against the FBI and Justice Department’s handling of the Russia investigation, including Rep. Matt Gaetz (R-Fla.). Following Ryan’s comments, Gaetz lashed out at those “carrying water” for the Justice Department.

Next week, senior law enforcement officials plan to brief the Gang of Eight — a group that includes the top Republicans and Democrats in each chamber, as well as the top Republicans and Democrats on their respective intelligence committees — about the early stages of the FBI probe. It is another attempt to satisfy GOP lawmakers — chief among them House Intelligence Committee Chairman Devin Nunes (R-Calif.) — who have accused the FBI of misusing its surveillance powers to go after Trump advisers.

Democrats have argued that the GOP’s complaints with the FBI and the Justice Department are part of a campaign to help the White House discredit the Russia probe, which is led now by special counsel Robert S. Mueller III.

Justice Department officials vehemently deny accusations of surveillance abuses, but they have said that turning over sensitive classified documents to lawmakers could lead to information leaks and endanger sources and methods.

For more than a month, the two sides have battled over the secret files regarding a confidential FBI source, Stefan A. Halper, who aided the Russia probe and repeatedly contacted Trump advisers in 2016. That disagreement, and some of the details that emerged, led the president to accuse the FBI of political spying.

Next week’s briefing will once again seek to settle that question, but it will happen over the objections of some Democrats. Rep. Adam B. Schiff (Calif.), the House Intelligence Committee’s ranking Democrat, said Thursday that it was a “mistake” for the Justice Department to have shared investigative materials about an ongoing matter in the first place.

“After the Speaker conceded only yesterday that the President’s claims of embedded spies were false, the further disclosure of investigative materials is inexplicable,” Schiff said in a statement.

“The DOJ is now reinforcing a precedent it will have to live with, whether the Congress is in Republican or Democratic hands, of providing materials in pending or closed cases to the legislative branch upon request,” Schiff’s statement says.

In late May, Deputy Attorney General Rod J. Rosenstein briefed senior members of both parties about how the FBI pursued the Russia counterintelligence probe. Next week’s follow-up is designed in part to answer questions raised by Ryan.

A senior Justice Department official said next week’s briefing will allow lawmakers “to review certain supporting documents that were made available during the prior briefing.” Officials “are prepared to brief members on certain questions specifically raised by the speaker and other members. The department and FBI will also provide the documents that were available for review but not inspected by the members at the previous briefing, along with some additional material,’’ the official said.

The Justice Department’s decision to provide multiple briefings on the subject is a significant departure from its initial stance after receiving a subpoena from Nunes. The senior official said the agency believes it can provide information “directly responsive to congressional inquiries in a manner that is consistent with its national security and law enforcement responsibilities, and is pleased to do so.”

Democrats have voiced concerns that such briefings could allow the president’s legal team to get access to sensitive details of the investigation. This week, Democratic members of the Gang of Eight sent a letter to the FBI and Justice Department seeking assurances that “outside of an appropriate judicial proceeding,” neither the president nor members of his staff or legal team would be briefed on classified information about the FBI’s source.