"Given the extraordinary public interest in the matter, the Attorney General made a decision to release the report's bottom-line findings and his conclusions immediately - without attempting to summarize the report - with the understanding that the report itself would be released after the redaction process", the Justice Department statement said.
At the same time, Barr said the prosecutor had reached no conclusion whether Trump, as president, had obstructed justice in trying to thwart the investigation.
"Given the extraordinary public interest in the matter, the Attorney General chose to release the report's bottom-line findings and his conclusions immediately - without attempting to summarize the report - with the understanding that the report itself would be released after the redaction process", the Justice Department statement said.
"The Special Counsel's investigation did not find that the Trump campaign or anyone associated with it conspired or coordinated with Russian Federation in its efforts to influence the 2016 USA presidential election", Barr's letter said. Trump has claimed the report totally exonerates him, "no collusion, no obstruction, no nothing".
US President Donald Trump waves while walking on the South Lawn of the White House before boarding Marine One in Washington, DC, on Oct 26, 2018.
"The House Appropriations Committee, funds the entire federal government, and we have to listen to the testimony from the executive branch officers who come in present their proposed budgets and tell us what they want to spend money on etc...so as part of funding the Justice Department, we have the Attorney General coming in and talking about the President's budget for that department".
He accused Nadler of being hypocritical for suggesting Barr was biased.
Barr's distillation "appears to minimise the implications of the report as to the president", said Nadler.
Yet Barr also conceded that Mueller did compile evidence of obstruction, and quoted the special counsel as saying that: "While this report does not conclude that the president committed a crime, it also does not exonerate him".
The Kremlin has consistently denied any involvement in the 2016 USA presidential elections.
Trump, who declared a "complete and total exoneration" when Barr announced Mueller's conclusions, said this week that Democrats "are fighting hard to keep the Witch Hunt alive".
All of those categories give Barr significant latitude to decide what to leave in and what to take out of the report's public version, none more so than the grand jury material.
Many Democrats and legal observers see Barr as an improper actor in the handling of the Mueller report.
On Friday, the Justice Department, commenting on a fresh ruling in a case on grand jury secrecy, signalled its stance against that.