The Obama administration has slapped sanctions on Russia after its alleged efforts to influence the 2016 US presidential elections.
The US expelled 35 Russian diplomats and imposed sanctions on two of its intelligence services.
The sanctions are the strongest ever taken by the US against a state-sponsored cyber attack.
The sanctions will give the President-elect Donald Trump little room for maneuver on the issue once he takes office in January 2017.
Earlier Trump had suggested that Russia was not behind the attacks but rather anyone with a computer could have been behind the alleged attacks.
President Obama also said that his administration would soon release evidence linking Russian intelligence officials to the cyber attacks ahead of US elections in November.
An investigation carried out by three of the US's main investigative agencies, the FBI, the NSA and the Department of Homeland Security, has uncovered evidence of Russian involvement.
In a rare instance, the call for sanctions against Russia was a bipartisan one, with a number of Republicans backing the move.
The Vice-President Joe Biden has even suggested that while these sanctions have been revealed to the media and hence the public, the US may also be considering covert repercussions.
Among the Russian officials sanctioned are: immediately impose sanctions on four Russian intelligence officials: Igor Valentinovich Korobov, the current chief of a military intelligence agency, the GRU, and three deputies -- Sergey Aleksandrovich Gizunov, the deputy chief of the GRU; Igor Olegovich Kostyukov, a first deputy chief, and Vladimir Stepanovich Alekseyev, also a first deputy chief of the GRU.
The Obama government also sanctioned the Special Technologies Center, a firm called Zor Security, and the Autonomous Non-commercial Organization Professional Association of Designers of Data Processing Systems.
Russians will also be cut-off from two Russian government-owned compounds in in Maryland and in New York.
Russian officials have maintained that their government had nothing to do with hacks, and have denied the Obama administration's accusation that the Russian government was trying to influence the US presidential election.
