Robert Mueller's report on Russia probe delivered to U.S. attorney general

Special counsel Robert Mueller on Friday turned over his long-awaited final report on the contentious Russia investigation that has cast a dark shadow over Donald Trump's presidency, entangled Trump's family and resulted in criminal charges against some of the president's closest associates.

The report will now be reviewed by U.S. Attorney General William Barr, who has said he will write his own account communicating Mueller's findings to Congress and the public as early as this weekend.

"I am reviewing the report and anticipate that I may be in a position to advise you of the special counsel's principal conclusions as soon as this weekend," Barr said in his letter to the top Republicans and Democrats on the House and Senate judiciary committees.

The comprehensive reportstill confidential for now marks the end of Mueller's probe but sets the stage for big public fights to come.

It's not known whether Mueller's report answers the core questions of his investigation: Did Trump's campaign collude with the Kremlin to sway the 2016 presidential election in favour of the celebrity businessman? Also, did Trump take steps later, including by firing his FBI director, to obstruct the probe?

An unnamed source told The Associated PressMueller did notrecommendany further indictments in the Russia probe.

Mueller, a former FBI director,brought charges against three companies andsix aides and advisers to the president.

Lawmakers from both parties called for prompt release of the report to key congressional committees and to the American public.

Senate Judiciary Committee Chairman Lindsey Graham expects that he and the panel's top Democrat, Sen. Dianne Feinstein, will be briefed "in the coming days" about Mueller's report.

The Democratic chairs of six House committees are demanding that the Justice Department release the full report "without delay."

The Democrats say since the Justice Department asserts a sitting president can't be indicted, Barr's failure to release evidence of criminal or other misconduct by President Trump "would raise serious questions about whether the Department of Justice policy is being used as a pretext for a cover-up of misconduct."

The six chairs are Jerrold Nadler of Judiciary and Eliot Engel of Foreign Affairs; Elijah Cummings of Oversight and Reform; Adam Schiff of the Intelligence Committee, Maxine Waters of Financial Services and the Ways and Means Committee's Richard Neal.

One top Republican, Sen. Chuck Grassley of Iowa, saidthe findings of the special counsel's Russia investigation must be made public to end the "speculation and innuendo" that hangs over Trump's administration.

The former Judiciary Committee chairman saidwhile it's clear the Russians "tried to meddle in our democratic processes," he still hasn't seen any evidence of collusion.

When the Justice Department announced the arrival of Mueller's report, Trump was at his Mar-a-Lago property in Florida. Hislawyers say they are "pleased" Mueller has delivered his report.

"We're pleased that the Office of Special Counsel has delivered its report to the Attorney General pursuant to the regulations. Attorney General Barr will determine the appropriate next steps," saidRudy Giuliani and Jay Sekulow in a joint statement.

Other Trump investigations

The conclusion of Mueller's investigation does not remove legal peril for the president. Trump faces a separate Justice Department investigation in New York into hush money payments during the campaign to two women who say they had sex with him years before the election. He's also been implicated in a potential campaign finance violation by his former lawyer, Michael Cohen, who says Trump asked him to arrange the transactions. Federal prosecutors, also in New York, have been investigating foreign contributions made to the president's inaugural committee.

No matter the findings in Mueller's report, the investigation has already illuminated Russia's assault on the American political system, painted the Trump campaign as eager to exploit the release of hacked Democratic emails and exposed lies by Trump aides aimed at covering up their Russia-related contacts.

The special counsel brought a sweeping indictment accusing Russian military intelligence officers of hacking Democrat Hillary Clinton's campaign and other Democratic groups during the 2016 election. He charged another group of Russians with carrying out a large-scale social media disinformation campaign against the American political process that also sought to help Trump and hurt Clinton.

Closer to the president, Mueller secured convictions against a campaign chairman who cheated banks and dodged his taxes, a national security adviser who lied about his Russian contacts and a campaign aide who misled the FBI about his knowledge of stolen emails.

Cohen, the president's former lawyer, pleaded guilty in New York to campaign finance violations arising from the hush money payments and in the Mueller probe to lying to Congress about a Moscow real estate deal. Another Trump confidant, Roger Stone, is awaiting trial on charges that he lied about his pursuit of Russian-hacked emails ultimately released by WikiLeaks. It's unclear whether any of the aides who have been convicted, all of whom have pleaded guilty and co-operated with the investigators, might angle for a pardon. Trump has left open the idea of pardons.

Along the way, Trump lawyers and advisers repeatedly evolved their public defences to deal with the onslaught of allegations from the investigation. Where once Trump and his aides had maintained that there were no connections between the campaign and Russia, by the end of the probe Giuliani was routinely making the argument that even if the two sides did collude, it wasn't necessarily a crime.

Equally central to Mueller's work is his inquiry into whether the president tried to obstruct the investigation. Trump, facing political peril from the inquiry, has usedTwitter, campaign-style speeches and comments to news media toassail Mueller, accusing him of running a politically motivated, "rigged witch hunt," going "rogue," surrounding himself with"thugs" and having conflicts of interest.

The president, speaking to reporters on the White House lawn before leaving for meetings at his Florida estate, again repeated his claim that: "There was no collusion. There was no obstruction. Everybody knows it. It's all a big hoax. It's all a witch hunt."

But Trump also took certain acts as president that caught Mueller's attention and have been scrutinized for possible obstruction.

One week before Mueller's appointment, Trump fired FBI Director James Comey, later saying he was thinking of "this Russia thing" at the time.

He mercilessly harangued former attorney general Jeff Sessions for recusing from the Russia investigation two months before Mueller was named special counsel, a move that left the president without a perceived loyalist atop the probe. And he helped draft a misleading statement on Air Force One as a Trump Tower meeting between his eldest son and a Kremlin-connected lawyer was about to become public.

The meeting itself became part of Mueller's investigation, entangling Donald Trump Jr. in the probe. Mueller's team also interviewed the president's son-in-law, Jared Kushner, multiple times.

Even as Trump blasted Mueller's team, his White House and campaign produced thousands of documents for the special counsel, and dozens of his aides were interviewed. The president submitted written answers to Mueller regarding the Russia investigation, but he refused to be interviewed.