The long-awaited report by Robert Mueller made no judgment on whether President Trump obstructed justice but William Barr, the USA attorney-general, said in a letter to Congress that Mr Trump would not face any charges.
Republican Senator Lindsey Graham, who has been sharply critical of the president in the past, tweeted that it was a "great day for President Trump and his team".
In a major political victory for Trump, who quickly hailed the announcement as "complete and total exoneration", Mueller's almost two years of investigation ended with a finding that no one in Trump's campaign "conspired or coordinated with the Russian government", according to a summary of Mueller's findings.
After consulting with other department officials, Barr said he and his deputy, Rod Rosenstein, determined the evidence "is not sufficient to establish that the president committed an obstruction of justice offense".
Between May 17, 2017 - the day Mueller was appointed Special Counsel - through September 30, 2018, his office spent $12,287,852.
"While this report does not conclude that the President committed a crime, it also does not exonerate (clear) him", the report stated.
But on the issue of whether justice was obstructed, Mr Mueller's report says: "While this report does not conclude that the president committed a crime, it also does not exonerate him".
House Speaker Nancy Pelosi of Calif., speaks at an Economic Club of Washington luncheon gathering in Washington, March 8, 2019.
Rudy Giuliani, one of Donald Trump's lawyers, told CNN the report "completely exonerated" the president, while White House press secretary Sarah Sanders tweeted that it was a "total and complete exoneration". Barr did not provide details of the evidence, but said most of it is publicly known. "It was a complete and total exoneration". They say Trump directed his personal lawyer Michael Cohen to arrange illegal hush-money payments as a way to quash potential sex scandals during the campaign.
For now, Mueller has said Trump didn't commit a crime.
The Special Counsel took up the question after Trump fired FBI Director James Comey over the Russian Federation investigation and after Comey claimed that Trump had asked him to stop investigating his former national security advisor, Michael Flynn.
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"Maybe what he was doing was leaving it up to the Hill to make a political determination", said Jeffrey Jacobovitz, a Washington white-collar attorney. Instead, Barr said, it "sets out evidence on both sides of the question".
Trump's former campaign chairman, Paul Manafort, was sentenced for obstruction of justice and conspiracy in September.
The House Judiciary Committee chairman says Congress needs to hear from Barr about his decision and see "all the underlying evidence".
That conclusion was based on Mueller's investigation, Barr said.
But that's just a function, it seems, of the president's flawed temperament.
The Special Counsel investigation led to the indictments of 37 individuals and entities, mostly Russian operatives and a handful of former Trump associates.
The highly anticipated summary of Mueller's investigation was sent to Congress on Sunday.
Barr said investigators didn't find that.
"For me or anyone to have an informed opinion on the substance of whether that opinion by Barr.is right, you need to know more about the evidence", Sandick said. Democrats are demanding full disclosure and vowing to compel the attorney general to comply.
Mueller's central mission has been to determine if Russian efforts to interfere in the 2016 election were aided or assisted in any way by Americans, including people close to Trump.
One of those actions included, for example, firing his Federal Bureau of Investigation director James Comey in May 2017.