U.S. Attorney General William Barr will not send his summary of special counsel Robert Mueller's report to Congress on Saturday, according to multiple media reports.

Media reports were quoting a senior Department of Justice (DOJ) official, who spoke on condition of anonymity because the person was not authorized to publicly discuss the review process.

Mueller has finished his inquiry into alleged Russian interference in the 2016 U.S. presidential election by submitting a confidential report to Barr on Friday.

Barr, who reportedly arrived at the Department of Justice building in Washington, DC, Saturday morning, is reviewing Mueller's findings. He told lawmakers Friday that he may provide Congress with the "principal conclusions" this weekend.

The DOJ official told media that Barr was working with advisers to determine what to include in the summary to Congress, adding that the attorney general will not deliver it on Saturday.

Mueller was appointed by Deputy Attorney General Rod Rosenstein in May 2017 to lead an inquiry into possible collusion between Donald Trump's campaign and Moscow during the 2016 presidential election and whether the president obstructed justice, among other things.

The investigation has shadowed the White House for nearly two years, as it has led to felony charges against 34 people, including six Trump associates, and three entities, triggering fierce criticism from the president and his political allies.

Russia has denied any meddling in the 2016 election.

(Top photo: Special Counsel Robert Mueller departs surrounded by police and security after briefing members of the U.S. Senate on his investigation into potential collusion between Russia and the Trump campaign on Capitol Hill in Washington, DC, June 21, 2017. /VCG Photo)