US Special Counsel Robert Mueller is expected on Friday to provide new details on how two of President Donald Trump's closest former aides have helped or hindered his probe into possible collusion between Russia and Trump's 2016 election campaign.
Mueller last month accused Trump's former campaign chairman, Paul Manafort, of breaching a plea bargain agreement by lying to prosecutors, and he will submit information on those alleged lies in a filing to a federal court in Washington.
The filing could shed new light on Manafort's business dealings or his consulting for pro-Kremlin interests in Ukraine.
Manafort, who maintains he has been truthful with Mueller, managed Trump's campaign for three months in 2016.
Also on Friday, Mueller's office and the US Attorney for the Southern District of New York are scheduled to file sentencing memos on Michael Cohen, Trump's former personal lawyer.
Cohen pleaded guilty to financial crimes in a federal court in New York in August, and last week he pleaded guilty to lying to Congress in a Mueller case. Sentencing for all of those charges will be handled by one judge in New York.
Mueller may disclose new information to supplement Cohen's admission last week that he sought help from the Kremlin for the proposed construction of a Trump skyscraper in Moscow late into the 2016 campaign.
The Mueller probe has infuriated Trump, who has regularly issued tweets criticizing the special counsel and his team.
The president has denied any collusion between his campaign and Russia, and accuses Mueller's prosecutors of pressuring his former aides to lie about him, his election campaign and his business dealings. Russia has denied meddling in the 2016 US election.
The president has called Cohen a liar and "weak person."
In new tweets on Friday, Trump again questioned prosecutors and accused federal investigators and senior officials of having conflicts of interest, without offering any evidence.
Trump said his lawyer, former New York City Mayor Rudy Giuliani, would release a response to the report that Mueller is expected to finalise in the coming months.
Trump's controversial firing of Comey in May 2017 prompted the appointment of a special counsel to continue the Russia probe
"We will be doing a major Counter Report to the Mueller Report," Trump tweeted.
Representatives for the US Justice Department and Mueller's office declined to comment on Trump's tweets.
Renato Mariotti, a former federal prosecutor, said he was looking to see if Mueller's prosecutors offer evidence that directly or tacitly support Cohen's assertions that Trump directed him to make hush payments to women in violation of campaign finance law and that he let the White House know what he planned to tell Congress about the Moscow skyscraper project. Cohen now says he lied in that testimony.
"If the government does not contest that, it indicates that it is consistent with the evidence that they do have," Mariotti said, referring to Cohen's assertions. "It could be a big day."
Another target of Trump's ire, former FBI Director James Comey, arrived on Capitol Hill on Friday for a closed session of two panels in the US House of Representatives that are looking into the Justice Department's handling of investigations of Hillary Clinton's use of emails when she was secretary of state and Russia's meddling in the 2016 election.
It was Trump's controversial firing of Comey in May 2017 that prompted the appointment of a special counsel to continue the Russia probe and became a point of focus for Mueller's inquiry into whether Trump obstructed justice.
CNN reported on Friday that Mueller questioned White House Chief of Staff John Kelly in recent months with a focus on an episode related to the obstruction of justice probe.
Trump announced on Friday that he had chosen former US Attorney General William Barr to once again lead the Justice Department. If confirmed by the Senate, Barr, who has defended Comey's firing, would be put in charge of Mueller.
Barr would take over just as Mueller's investigation appears to be gathering steam.
The filings on Cohen and Manafort will follow a sentencing memo earlier this week regarding Trump's former national security adviser, Michael Flynn.
In the memo, Mueller praised Flynn for providing "substantial" cooperation and argued that he should receive no prison time, a move widely seen by legal experts as a message to other would-be cooperators that assistance would be rewarded.
Cohen is hoping prosecutors make a similar recommendation, emphasizing in a court filing last week that his decision to cooperate came in the face of fierce criticism by Trump of Mueller's probe.
Cohen's lawyers also argued that celebrities engaged in similar tax evasion cases - one of the core charges against him - have faced only civil penalties. The lawyers said his financial crimes were unsophisticated, noting no overseas accounts were used.
Manafort, in addition to allegedly lying to Mueller, was convicted in a separate case in Virginia for a sophisticated bank and tax fraud scheme that included tens of millions of dollars in payments for his work in Ukraine.
Mariotti, the former prosecutor, said he expected Mueller's office to be unsparing in its submission in Manafort's case on Friday.
"They want the judge to throw the book at Manafort, sending a message to him and everyone else," he said.