The attorney general's decision on what to finally disclose seems nearly certain to set off a fight with congressional Democrats, who want access to all of Mueller's findings - and supporting evidence - on whether Trump's 2016 campaign coordinated with Russian Federation to sway the election and whether the president later sought to obstruct the investigation.
Democrats are pushing for transparency on the report, pressuring Barr to release as much information as possible.
Pelosi said Congress must get Mueller's entire report so that the relevant committees can proceed with oversight and with potential legislation to address any issues the investigation may raise.
Mueller had earlier brought charges against 34 people and three companies, with prison sentences for some of Trump's ex-aides such as former campaign chairman Paul Manafort and former personal lawyer Michael Cohen. A Trump appointee, Barr told lawmakers on Friday that he is "committed to as much transparency as possible".
Sen. Mark Warner, D-Va., the vice chairman of the Senate intelligence committee, said Congress should get full access to the report.
The attorney general spent nine hours at the Justice Department on Saturday before leaving at around 7 p.m. (2300 GMT), CNN said.
The Russia investigation has shadowed Trump for almost two years and has ensnared his family and close advisers.
Trump, who has repeatedly called the Mueller probe a "witch hunt", has so far not tweeted on the news that the investigation is over. He denies collaborating with Moscow. Twenty-five Russians were indicted on charges related to election interference, accused either of hacking Democratic email accounts during the campaign or of orchestrating a social media campaign that spread disinformation on the internet.
Pakistan can not afford to be blacklisted, says PM Imran Khan
Troops from Azerbaijan, China, Saudi Arabia, Turkey, Bahrain and Sri Lanka also took part in the parade. The Exxon Company is engaged in exploration activity in the Pakistani sea, prime minister informed.
CVS to sell cannabis-based products in Kentucky
According to a new analysis by Cowen & Co. the global CBD market could grow all the way up to $16 billion by 2025 . CVS will also sell these products in Alabama, California, Colorado, Illinois, Indiana, Maryland and Tennessee.
Russia talks on Venezuela stall over the role of Maduro
He added that the United States is "not looking for anything other than taking care of a lot of people". The Russian side also intends to urge the USA to help in facilitating intra-Venezuelan dialogue.
The White House sought to keep its distance, saying Saturday it had not been briefed on the report. But many Democrats say Trump should not be immune from a public accounting of his behavior. "He's good, he's good".
As Newsweek's Nicole Goodkind reported, there will likely be two reports and, if any were released to the public, it is unlikely to be the one Mueller penned.
Political analysts expect the Mueller report to have a significant impact on the 2020 presidential campaign - how Democrats might be able to use it stop Trump being reelected and how Trump could use it if he is effectively cleared of wrongdoing.
"It is imperative for Mr. Barr to make the full report public and provide its underlying documentation and findings to Congress", the Democratic leadership said in a statement.
In his letter, Barr wrote he will discuss next steps on the report's release with his deputy, Rod Rosenstein, and Mueller - "to determine what other information from the report can be released to Congress and the public consistent with the law, including the Special Counsel regulations, and the Department's long-standing practices and policies".
The big question is whether the report contains allegations against Trump or exonerates him.
Barr arrived at the Justice Department's headquarters Saturday morning.
US intelligence agencies have concluded that Moscow meddled in the 2016 election with a campaign of email hacking and online propaganda aimed at sowing discord in the United States, hurting Clinton and helping Trump.