President Barack Obama yesterday ordered the expulsion of 35 Russian diplomats and sanctioned Russian intelligence officials who Washington believes were involved in hacking US political groups in the 2016 presidential election.
The measures mark a new low in US-Russian relations, which have deteriorated over serious differences on Ukraine and Syria.
It was not clear whether US president-elect Donald Trump, who has repeatedly praised Russian president Vladimir Putin, would seek to roll back the measures once he takes office nexc t month.
Mr Obama is seeking to deter Russia and other foreign governments from trying cyber attacks in the future to meddle in US politics, former officials and cyber security experts said.
The Russian foreign ministry said yesterday the sanctions were counter-productive and would harm the restoration of bilateral ties. Moscow denies the hacking allegation.
Mr Obama sanctioned two Russian intelligence agencies, the GRU and the FSB, four GRU officers and three companies "that provided material support to the GRU's cyber operations".
The US State Department is closing two Russian compounds in New York and Maryland that were used by Russian personnel for "intelligence-related purposes".
A senior US official told Reuters the move would affect the Russian embassy in Washington and consulate in San Francisco, with the Russians given 72 hours to leave the US.
Access to the two compounds, which are used by Russian officials for intelligence gathering, will be denied to all Russian officials as of noon today.
"These actions were taken to respond to Russian harassment of American diplomats and actions by the diplomats that we have assessed to be not consistent with diplomatic practice," the official said.
The State Department has long complained that Russian security agents and traffic police have harassed US diplomats in Moscow, and US Secretary of State John Kerry has raised the issue with Mr Putin.
It is understood that Russia's ambassador to the US, Sergey Kislyak, will not be one of those expelled.