In Wednesday's address-Mueller's first public statement since the start of the roughly two-year investigation into Russian interference in the 2016 election-the special counsel resigned from his role at the Justice Department and reiterated the findings of his office's report.
Following former special counsel Robert Mueller's comments on Wednesday, Democrats are doubling down on their calls for impeaching US President Donald Trump, based on their interpretation of Mueller's words.
Mr Trump has blocked the committee's subpoenas and other efforts to dig into the Trump-Russia issue, insisting Mr Mueller's report has settled everything. "There was insufficient evidence and therefore, in our Country, a person is innocent", Trump tweeted, moments after the special counsel's appearance.
The Trump re-election campaign released a statement by campaign manager Brad Parscale that said Mueller's remarks on Wednesday "fully and completely exonerated" Trump and that the "case is now closed".
"As set forth in our report, after that investigation, if we had confidence that the President clearly did not commit a crime, we would have said that", he said.
Mr Mueller made clear he was barred from indicting a sitting president and that it was Congress' job to hold the president accountable for any wrongdoing. Still, Mueller emphasized that he believes Justice Department guidelines would not have allowed him to bring criminal charges against a sitting president, adding that the "Constitution requires a process other than" that.
Nothing changes from the Mueller Report.
After the report was released, Barr appointed an attorney to examine the origins of the Russian Federation investigation, after numerous accusations from Trump that the investigation was a hoax.
Seth Moulton, one of the presidential candidates said, "Mueller did his job".
The statement will be at 11:00 (15:00 GMT), the justice department says.
He strongly indicated that Congress is the proper venue, not the criminal justice system, for deciding whether action should be taken against the president in connection with allegations that Mr Trump and aides obstructed the investigation.
Mueller's statement - his first and only before cameras since his appointment in May 2017 - came as the Trump administration and Democrats on Capitol Hill are locked in a constitutional showdown over congressional oversight authorities. President Andrew Johnson, who took over after Abraham Lincoln was assassinated in 1865, narrowly missed a conviction by a single vote, and Richard Nixon retired before what many considered a likely conviction could be delivered. But it also did not reach a conclusion on whether the president had obstructed justice.
Barr and former deputy Attorney General Rod Rosenstein subsequently determined Trump had not broken the law.
In an upcoming book, Siege: Trump Under Fire, controversial author Michael Wolf has claimed Mueller's team drew up a three-page obstruction indictment for Trump but decided not to pursue it. Wolff has cited documents he's seen, but a Mueller spokesperson, Peter Carr, told the Guardian newspaper on Wednesday that the documents as Wolff described "do not exist".
"That is unconstitutional. Even if the charge is kept under seal and hidden from public view - that too is prohibited". President Bill Clinton was acquitted on the charge of obstruction of justice, but the Senate was tied 50-50 as to whether or not he lied to Congress during the investigation.