 -- The classified report requested by President Barack Obama detailing Russia's alleged role in cyberattacks during U.S. presidential elections dating back to 2008 is now complete, and he is expected to receive the first briefing on its findings on Thursday afternoon, U.S. officials tell ABC News.

President-elect Donald Trump, who said last week he would receive his briefing on the matter on Tuesday or Wednesday of this week, is scheduled to receive his briefing on Friday. Both briefings will be conducted by the heads of relevant agencies, including the Office of the Director of National Intelligence, the National Security Agency, the FBI and the CIA.

U.S. officials denied claims from Trump that his special briefing was delayed so the U.S. intelligence community could strengthen its case against Russia. Officials instead said there may have been a scheduling disconnect or some confusion on the part of the Trump transition team.

Officials familiar with the report say an unclassified version of its findings is not expected to made public until Monday, the same day Congress gets its classified briefing. Although the unclassified version will be far less revealing, pushing the public findings into next week will likely prolong the ugly spat between Trump and Democrats and the intelligence community over who is responsible for the cyberattacks.

In recent weeks, Trump has repeatedly questioned the conclusions of the intelligence community, which on Oct. 7 stated publicly that it is "confident" Russia directed hacks of political organizations during the 2016 presidential election season.

In doubting the claims, Trump referred to the intelligence community's false conclusions about the presence of weapons of mass destruction in Iraq in the run-up to the Iraq War, and he has taken WikiLeaks founder and fugitive computer activist Julian Assange at his word that the Russians were not the source of the information leaked to his site.

"I know a lot about hacking," Trump said Monday at his Mar-a-Lago estate in Florida. "And hacking is a very hard thing to prove. So it could be somebody else. And I also know things that other people don't know, and so they cannot be sure of the situation," he said, apparently referring to the intelligence community.

On Thursday, Sen. John McCain, R-Ariz., is set to hold a Senate Armed Services Committee hearing with testimony from ODNI and NSA officials, who are not expected to comment at length on the new report before Obama is briefed.