Special counsel Robert Mueller on Friday delivered his report to Attorney General William Barr on Russia's election interference and possible collusion with Donald Trump's presidential campaign.
The handoff marks the long-anticipated end of the high-profile and highly guarded Russia probe nearly two years after it began.
No more indictments will be filed from the special counsel's office, nor will any more be recommended, a senior Justice Department official told NBC.
It remains unclear how much of the report will be made public, but Barr suggested Friday that at least portions of it will be released.
"The Special Counsel has submitted to me today a 'confidential report explaining prosecution or declination decisions' he has reached," Barr wrote in a letter to the leaders of the House and Senate Judiciary committees.
Barr wrote that he intends to consult with Deputy Attorney General Rod Rosenstein and Mueller "to determine what other information from the report can be released to Congress and the public consistent with the law."
"I remain committed to as much transparency as possible, and I will keep you informed as to the status of my review," Barr wrote.
He added: "I am reviewing the report and anticipate that I may be in a position to advise you of the special counsel's principal conclusions as soon as this weekend."
Scroll down or click here to read Barr's full letter.
Mueller was appointed by Rosenstein days after Trump abruptly fired former FBI Director James Comey, who had been in charge of the government's investigation into Russian interference in the 2016 presidential election.
The special counsel was authorized to look into Russian meddling and potential "links and/or coordination" with the Trump campaign, as well as "any matters that arose or may arise directly from the investigation." It was later revealed that the special counsel was investigating whether Trump himself obstructed justice.
A spokesman for the special counsel's office did not immediately respond to CNBC's request for comment.
In a tweet, White House press secretary Sarah Huckabee Sanders said, "We look forward to the process taking its course."
The president's lawyers, Jay Sekulow and former New York Mayor Rudy Giuliani, said in a statement: "We're pleased that the Office of Special Counsel has delivered its report to the Attorney General pursuant to the regulations. Attorney General Barr will determine the appropriate next steps."
Mueller's team has lodged indictments against 34 people and three companies. Five people, including Trump's former longtime personal attorney Michael Cohen and former campaign chairman Paul Manafort, have been sentenced to prison.
Trump has denied any wrongdoing related to Mueller's investigation. From its inception, he has decried the probe as a politically motivated "witch hunt."
Although the special counsel's probe has formally ended, a handful of federal cases lodged by Mueller remain active. Trump's longtime confidant Roger Stone, for instance, faces a Nov. 5 trial on charges of lying to Congress and witness tampering filed by Mueller's prosecutors.
Others, including Rick Gates, Manafort's former business partner, have yet to be sentenced.
Former federal prosecutor David Weinstein said it was too soon to draw conclusions about who had and had not been targeted by Mueller.
"Until we read the report, it is only speculation as to why certain people were not indicted and what evidence exists as to the interference, or lack of interference, by the Russian government," Weinstein told CNBC in an email.
"This does not mean that other DOJ components are finished working with the leads that were provided to them by the special counsel's office," Weinstein added.
Congress weighs in
Democrats called for transparency in statements following the news. They unanimously urged Barr to make the report as public as possible.
House Judiciary Chairman Jerry Nadler, D-N.Y., said in a tweet: "We look forward to getting the full Mueller report and related materials. Transparency and the public interest demand nothing less. The need for public faith in the rule of law must be the priority."
Senate Minority Leader Chuck Schumer, D-N.Y., and House Speaker Nancy Pelosi, D-Calif., released a joint statement calling on Barr to provide the documentation underlying the report to Congress:
"Now that Special Counsel Mueller has submitted his report to the Attorney General, it is imperative for Mr. Barr to make the full report public and provide its underlying documentation and findings to Congress. Attorney General Barr must not give President Trump, his lawyers or his staff any 'sneak preview' of Special Counsel Mueller's findings or evidence, and the White House must not be allowed to interfere in decisions about what parts of those findings or evidence are made public.
"The Special Counsel's investigation focused on questions that go to the integrity of our democracy itself: whether foreign powers corruptly interfered in our elections, and whether unlawful means were used to hinder that investigation. The American people have a right to the truth. The watchword is transparency."
House Intelligence Committee Chairman Adam Schiff, D-Calif., said on MSNBC that "the key question" now is whether Barr will "live up to the commitment he made to be as transparent as possible, which would require making public the Mueller report."
Sen. Mark Warner, D-Va., the top-ranking Democrat on the Senate Intelligence Committee, said in a statement that Barr should "swiftly prepare a declassified version of the report for the public. Nothing short of that will suffice."
"It is also critical that all documents related to the Special Counsel's investigation be preserved and made available to the appropriate Congressional committees," Warner added. "Any attempt by the Trump Administration to cover up the results of this investigation into Russia's attack on our democracy would be unacceptable."
Republicans concurred.
Senate Majority Leader Mitch McConnell, R-Ky., said he welcomed the announcement that the Russia probe had been completed:
"I welcome the announcement that the Special Counsel has finally completed his investigation into Russia's efforts to interfere in the 2016 elections. Many Republicans have long believed that Russia poses a significant threat to American interests. I hope the Special Counsel's report will help inform and improve our efforts to protect our democracy.
"I am grateful we have an experienced and capable Attorney General in place to review the Special Counsel's report. Attorney General Barr now needs the time to do that.
"The Attorney General has said he intends to provide as much information as possible. As I have said previously, I sincerely hope he will do so as soon as he can, and with as much openness and transparency as possible."
Senate Intelligence Committee Chairman Lindsey Graham, R-S.C., said the handoff "indicates that there were no areas of disagreement" between Mueller and top DOJ officials "regarding courses of action":
"The Department of Justice has notified me and Ranking Member Feinstein that the Mueller Report has been turned over to Attorney General Barr. This notification indicates that Attorney General Barr will pursue as much transparency as possible.
"Importantly, the notification also indicates that there were no areas of disagreement between the Attorney General or the Acting Attorney General and Special Counsel Mueller regarding courses of action. This information is specifically required to be disclosed by the regulations governing Special Counsel reports.
"I expect both Ranking Member Feinstein and I will be briefed more thoroughly about the report in the coming days.
"I will work with Ranking Member Feinstein and our House Judiciary Committee colleagues to ensure as much transparency as possible, consistent with the law.
"I have always believed it was important that Mr. Mueller be allowed to do his job without interference, and that has been accomplished."
Senate Intelligence Committee Chairman Richard Burr, R-N.C., was more terse: "I trust Special Counsel Mueller has conducted a fair and thorough investigation, and I look forward to reviewing his report."
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