Mueller report: AG William Barr's full press conference | USA TODAY

The Justice Department will release a redacted version of special counsel Robert Mueller's report on Russian interference in the 2016 presidential election Thursday, giving the public and Congress the deepest look yet into its investigation of President Donald Trump's campaign.

Prior to its release, Attorney General William Barr told reporters that Mueller's investigation confirmed that the Russian government sponsored efforts to illegally interfere with the 2016 presidential election but did not find that the Trump campaign or other Americans joined in its efforts.

“After nearly two years of investigation, thousands of subpoenas and hundreds of warrants and witness interviews, the special counsel confirmed that the Russian government sponsored efforts to illegally interfere with the 2016 presidential election, but did not find that the Trump campaign or other Americans colluded in those schemes,” Barr said. “So that is the bottom line.”

And Barr said Trump's actions during the probe were not so much obstruction as frustration with an investigation he thought was constraining his presidency.

“The president took no act that deprived the special counsel of the documents and witnesses necessary to complete his investigation,” Barr said.

The long-anticipated report is the culmination of a remarkable inquiry into whether the president's aides collaborated with the Russian government's efforts to sway the election in his favor.