President Trump's campaign "did not conspire with Russia during the 2016 election campaign," says Special Envoy Robert Mueller.
The summary of the Special Counsel's report published on Sunday "did not draw any conclusion" as to whether there was any obstacle to the judiciary.
It says: "Although this report does not rule out that the President has committed a crime, it also does not relieve him."
However, the Attorney General says that this is not a criminal offense.
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The report is the result of a two-year investigation by Mr Müller.
What is included in the report summary?
"The report outlines Russia's efforts to influence the election and the crimes committed," says Attorney General William Barr's letter to Congress.
"The Special Adviser did not find that a US person or Trump election official was conspiring or knowingly coordinating with Russia."
Mr. Barr ends his letter to Congress with the explanation that he will release more from the entire report, but that some of the material is subject to restrictions.
"Given these limitations, the schedule for processing the report depends, in part, on how quickly the department can identify the report [grand jury] Material that can not be published by law.
"I've asked the Special Counsel to help identify all the information in the report as soon as possible."
Mr. Barr has been thinking about the document since receiving it on Friday.
How was the reaction?
Congressman Jerry Nadler, Democratic Chairman of the House Judiciary Committee, stressed that the Attorney General does not rule out that Mr. Trump has obstructed the judiciary.
"Barr says the president may have acted to impede justice, but for an obstacle conviction, the government would need to prove beyond any doubt that a person acting with corrupt intent is involved in obstructive behavior."
The White House press secretary, Sarah Sanders, however, described the findings of the report as "a full and complete discharge of the President."
Mr. Trump's lawyer, Rudy Giuliani, said the report was "better than I expected".