US Attorney General William Barr pored over a special counsel report into Russian interference in the 2016 presidential election and whether the Trump campaign coordinated with Moscow, and was due to release key findings perhaps as early as Sunday.
Barr, the top US law enforcement official, aimed to transmit to Congress and the public a summary of Special counsel Robert Mueller's report by the end of the weekend.
He will not deliver the summary on Saturday, a Justice Department official said, leaving it likely that he will do so on Sunday.
There appeared to be initial good news for president Donald Trump and his inner circle, as Mueller did not bring any new indictments when handing over his report to Barr on Friday after a probe of almost two years.
That signals there might be no more criminal charges against Trump associates on the issue of whether the Trump campaign conspired with Russia to help ensure the Republican businessman's surprise election win against Democrat Hillary Clinton.
"Once we get the principal conclusions of the report, it's entirely possible that that'll be a good day for the president and his core supporters," Democratic senator Chris Coon told reporters on a conference call.
It was not immediately known what Mueller's report says about another strand of inquiry: whether Trump committed obstruction of justice to hinder the Russia investigation by acts such as firing then FBI director James Comey in 2017.
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.
None of those charges, however, directly related to the question of collusion between the campaign and Moscow.
Trump and his core team still face legal risks even if the report does not find that they committed crimes, and congressional Democrats on Saturday vowed to keep looking into his activities.
Trump's business, his charity and presidential transition operation remain under investigation, said Coons, a member of the senate Judiciary Committee.
Other prosecutors have picked up strands of the Mueller probe, most notably the US Attorney's Office for the Southern District of New York which is looking into Trump's business practices and financial dealings.
Key Findings
On Saturday, Barr and his deputy were working closely with principal advisers to determine what to include in a letter to Congress to present the key findings of Mueller's report.
Under Department of Justice regulations, Barr is empowered to decide how much to disclose publicly. A Trump appointee, Barr told lawmakers on Friday that he is "committed to as much transparency as possible."
The attorney general spent nine hours at the Justice Department on Saturday before leaving at around 7 pm (2300 GMT), CNN said.
Trump, at his Mar-a-Lago, Florida, resort for the weekend, remained uncharacteristically silent about the completion of the investigation that has cast a shadow over his two years in the White House.
He has frequently derided the Russia investigation as a "witch hunt." He denies collaborating with Moscow. Russia says it did not interfere in the election.
Spokesman Hogan Gidley told reporters that the White House still has not received or been briefed on Mueller's report.
The president had no public events scheduled on Saturday and played golf with musician Kid Rock. "He's fine," Gidley said when asked by reporters how Trump was feeling. "He's good, he's good." Gidley declined to say whether Trump had talked about the Mueller report while golfing.
A large pro-Trump float behind a flatbed truck pulled up to the golf course about an hour after he arrived, adorned with American flags and "Trump 2020" signs.
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 re-elected and how Trump could use it if he is effectively cleared of wrongdoing.
The big question is whether the report contains allegations against Trump or exonerates him. Even if Mueller has outlined serious wrongdoing by Trump, the Justice Department has a policy that sitting presidents cannot face criminal charges.
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.
US House of Representatives speaker Nancy Pelosi, a Democrat, said Barr's offer to provide congressional committees with a summary of the report's conclusions is insufficient and that "Congress requires the full report and the underlying documents."
House Democrats have sent letters to the Justice Department to ensure Mueller report documents are preserved in case lawmakers need to see them, Representative Ted Lieu told MSNBC.