President Barack Obama has ordered an investigation into a series of cyber-attacks, blamed on Russia, that shook the US election season.
The hacks targeted emails at the Democratic Party and a key aide to presidential nominee Hillary Clinton.
In October, US government officials pointed the finger at Russia, accusing it of meddling in the US vote.
According to a secret CIA assessment reported by the Washington Post, Russia intervened to help Donald Trump win.
The allegation was flatly dismissed by the transition team for Mr Trump, who will succeed Mr Obama in the White House next month.
Russian officials have denied the hacking accusations.
