US President-elect Donald Trump has said his team will have a “full report on hacking within 90 days”.
He again dismissed as fake a document alleging Russia has damaging information about him.
Mr Trump tweeted that the dossier includes “totally made up facts by sleazebag political operatives, both Democrats and Republicans - FAKE NEWS!”
He added “Russia says nothing exists” and that the allegations will never be proved.
US intelligence officials briefed Mr Trump and President Barack Obama on a dossier that includes unproven information about close co-ordination between Mr Trump’s inner circle and Russians about hacking into Democratic accounts
It also contained unproven claims about alleged unusual sexual activities by Mr Trump attributed to anonymous sources.
Mr Trump also said Democrats should not be “complaining” about the FBI’s handling of Hillary Clinton because she is “guilty as hell” and should not have been allowed to run for president in the first place.
The president-elect appears to have been responding to a Justice Department inquiry into the FBI’s handling of its investigation into Mrs Clinton’s private email server, and the FBI’s decision to release information about the review days before the election.
Clinton aides have blamed the FBI for influencing voters.
Mr Trump tweeted: “Based on the information they had she should never have been allowed to run - guilty as hell. They were VERY nice to her.”
He added that Mrs Clinton lost because she “campaigned in the wrong states - no enthusiasm!”
Mr Trump will be sworn in on Friday in a ceremony Mrs Clinton plans to attend as a former first lady.