Vice-president Joe Biden told President-elect Donald Trump Thursday to "grow up."
Biden dismissed Trump's complaint on Twitter about how the Obama administration has handled the transition. The vice president told "PBS NewsHour" in an interview that it's time for Trump "to be an adult."
Biden said to Trump: "You're president. You've got to do something. Show us what you have."
Biden had criticised two of Trump's recent messages in which he labelled Senate minority leader of the Democrats Chuck Schumer as "head clown" and another in which the President-elect criticised President Barack Obama for his "incendiary comments".
"It's going to be much clearer what he's (Trump) for and against, and what we're for and against, now that it's going to get down to actually discussing in detail these issues that affect people's lives," Biden said. The vice president also said it was "dangerous" for Trump to be skeptical of US intelligence agencies.
Biden also said it's "absolutely mindless" for a president not to have confidence in or listen to the intelligence agencies.
The vice president said it would be legitimate to question intelligence and ask for more detail or disagree. But he said that's different than Trump claiming he knows more than the intelligence agencies.
Biden said that's like saying, "I know more about physics than my professor." He says that's worrisome, but he assumes Trump's behavior will change. He said that Trump is surrounding himself with "very smart people" like retired Marine Corps Gen. James Mattis, the billionaire businessman's pick for defense secretary.
Biden talked about recent US intelligence agency reports about how Russia may have meddled in the presidential election.
Biden said: "There is overwhelming consensus in the community and overwhelming evidence supplied by the community that Russia did engage in an effort to impact on the elections.
"There is no evidence that they actually tampered with voting booths or tampered with voting roles.
"But there is clear evidence that they in fact were engaged in activities designed to try to impact the outcome of the election."
New York Republican Representative Chris Collins, a member of Trump's transition executive committee, denounced Biden's response.
"That's a pathetic response," Collins said on Thursday.
"I think it's beneath the Office of the Vice President. It shows just the angst of the loss of this election by Obama, Hillary Clinton and Joe Biden. Trump is the adult in the room."
This isn't the first time Biden has been outspoken against Trump.
Biden in October slammed Trump saying the Republican presidential nominee "lacks any sensibilities about the American people".
"He's not a bad man," Biden said at the time. "But his ignorance is so profound, so profound."