The United States has imposed sanctions on 19 Russian organisations and individuals, accusing them of cyber-attacks and interference in the 2016 US election.
US President Donald Trump Photo: AFP
The move is being described in Washington as the strongest action taken so far by the Trump administration against Moscow.
Those targeted include the Russian military intelligence agency GRU and the St Petersburg-based Internet Research Agency, which is accused of engineering an online disinformation campaign to sway the election result.
Also targeted are Yevgeny Prigozhin - an oligarch who allegedly ran the agency and has close links to Russian President Vladimir Putin - and 12 of his staff charged last month by the Justice Department special counsel, Robert Mueller.
"The IRA [Internet Research Agency] created and managed a vast number of fake online personas that posed as legitimate US persons to include grassroots organisations, interest groups, and a state political party on social media," the Treasury Department statement said on Thursday.
"Through this activity, the IRA posted thousands of ads that reached millions of people online."
Under the sanctions, any assets the individuals and entities may have in the US are frozen, and American citizens are prohibited from doing business with them.
Treasury Secretary Steven Mnuchin accused the Russians of "destructive cyber-attacks, and intrusions targeting critical infrastructure".
He said the sanctions would target "ongoing nefarious attacks" by Russia.
The Trump administration also accused Russia on Thursday of an ongoing operation to hack and spy on the US power utilities.
US officials said the Russians hacked computer systems to conduct "network reconnaissance" of systems that run the American electricity grid and other industrial infrastructure.
Under the US sanctions, the Russian Federal Security Service, or FSB, and six of its employees are subjected to penalties for cyber-attacks.
The US treasury secretary said there would be additional sanctions to hold Russian "officials and oligarchs accountable for their destabilising activities".
He did not specify when these penalties would be imposed, but stated they would sever the individuals' access to the US financial system.
Russian Deputy Foreign Minister Sergei Ryabkov said Moscow was calm about the new sanctions, according to Interfax news agency.
Mr Ryabkov said Moscow had already begun drawing up retaliatory measures.
At the White House, where he is hosting Irish Prime Minister Leo Varadkar, President Trump agreed with British, French and German allegations that the Kremlin was behind the poisoning of a former spy in southern England.
The UK has blamed Russia for the attack and is expelling 23 of its diplomats, but Moscow denies all involvement.
"It certainly looks like the Russians were behind it," said Mr Trump, "and we're taking it very seriously."
- BBC
