On New Year's Eve, Trump said that he knows "things that other people don't know, and so they cannot be sure of the situation."
Pressed by a reporter for details, Trump said, "You'll find out Tuesday or Wednesday."
But as Wednesday came to a close, Trump hadn't revealed any more details about the hacking of his campaign opponents, admitting only — in a tweet — that "somebody hacked the DNC" and alleging that the Democratic National Committee had weak cyberdefenses.
But there was no delay, according to U.S. officials; the briefing was always scheduled for Friday.
Referring to the source who leaked stolen emails from the DNC to his website, Assange said the "source is not the Russian government, and it is not a state party."
That appearance and subsequent tweets from Trump showed an alliance that just a few years ago would have seemed unthinkable.
Regardless, U.S. officials said Assange doesn't know what he's talking about.
"There's no way that Assange would have any idea who was behind dropping this information off," said Matt Olsen, a former director of the National Counterterrorism Center and an ABC News contributor. "The Russian intelligence services are clearly capable of hiding their tracks."
And with only about two weeks until Trump becomes commander in chief, the nation's top Democrat after President Barack Obama leaves the White House is warning Trump that he could face payback once in office.