US election hack: Trump to be briefed on classified report on Russia

The nation's top intelligence officials are making their most detailed and persuasive case yet to President-elect Donald Trump that Russia interfered in this year's US political process.

The officials, Director of National Intelligence James Clapper, CIA Director John Brennan and FBI Director James Comey, are preparing to point to multiple motives for Moscow's alleged meddling as they brief Trump on their classified report today in New York.

President Barack Obama received a briefing on Thursday, and a declassified version of the report is expected to be released at some point.

Since winning the election, Trump has repeatedly questioned intelligence officials' assessments that Russia was behind the hacking of the Democratic National Committee and individual Democrats like Hillary Clinton campaign chairman John Podesta.

Trump remained dubious about the assertion even on the eve of his intelligence briefing, asking how officials could be "so sure" about the hacking if they had not examined DNC servers. "What is going on?" he wrote on Twitter.

A senior law enforcement official said the FBI repeatedly stressed to DNC officials the importance of obtaining direct access to the servers "only to be rebuffed until well after the initial compromise had been mitigated." The official said the FBI had to rely on a "third party" for information, but did get access to the material it needed.

The Washington Post, citing anonymous US officials, reported yesterday that intelligence agencies have identified parties who delivered stolen Democratic emails to WikiLeaks.

The officials also said there were disparities between efforts to infiltrate Democratic and Republican networks, and said the US intercepted communications in which Russian officials celebrated Trump's victory. It was not clear which of those details were included in the classified report.

Ahead of the briefing, Trump moved to fill out his own intelligence leadership team, tapping former Indiana Sen. Dan Coats to lead the Office of the Director of National Intelligence, according to a person with knowledge of the decision.

Coats served as a member of the Senate Intelligence Committee before retiring from Congress last year. If confirmed by the Senate, he would oversee the umbrella office created after the 9/11 attacks to improve coordination of US spy and law enforcement agencies.

The person with knowledge of Trump's decision, as well as others who spoke to The Associated Press about intelligence matters involving Trump, were not authorised to discuss the matters publicly and spoke on condition of anonymity.

Coats, a 73-year-old Capitol Hill veteran, served eight years in the House before moving to the Senate in 1989 to take Dan Quayle's place when he became vice president. He stayed in the Senate until 1998, then left to become a lobbyist.