The Mueller report into suspected collusion between Donald Trump and Russia has found there is no evidence that the president committed a crime.
However, the report also does not exonerate the president of obstruction of justice - with the chairman of the US House judiciary committee, Jerry Nadler, saying the report "is putting matters squarely in Congress' court".
Nadler tweeted that the Justice Department "determined not to make a traditional prosecutorial judgement".
Attorney General William Barr released a four-page summary of Mr Mueller's report on Sunday afternoon.
Barr said evidence gathered in the investigation "is not sufficient to establish" that Trump committed obstruction of justice.
He said Mueller did not reach any conclusions in evaluating the president's conduct, leaving it to the Justice Department.
Barr said that he and Deputy Attorney General Rod Rosenstein reached their conclusion without considering constitutional questions regarding bringing criminal charges against a sitting president.
The special counsel wrapped up his investigation on Friday, bringing to a close a probe that has shadowed Trump for nearly two years.