Image source, ReutersImage caption, Nato has halved the size of the Russian contingent at its Brussels headquarters from 20 to 10
Nato has expelled eight Russian diplomats it says have been working secretly as intelligence officers.
The military alliance has also halved the size of Moscow's mission working at its Brussels headquarters to 10.
It is the first time Nato has taken such action against Moscow since it expelled seven Russian diplomats from the mission in the wake of the 2018 Salisbury spy poisonings.
Russian officials accused the West of using Moscow as a "bogeyman".
""The collective West is continuing its policy of diplomatic confrontation with Russia," said Russian Deputy Foreign Minister Alexander Grushko.
"After the dramatic end of the Afghan era, how can they can get by without the bogeyman of the 'Russian threat'? – They can't."
Sky News reported that the expulsions came "in response to suspected malign Russian activities, including killings and espionage".
Relations between Nato and Russia have been strained since Moscow annexed Ukraine's Crimean peninsula in 2014.
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The latest move means the number of people Russia can accredit at the organisation will be halved from 20 at the end of the month.
"We can confirm that we have withdrawn the accreditation of eight members of the Russian mission to Nato, who were undeclared Russian intelligence officers," a Nato official said.
"Nato's policy towards Russia remains consistent. We have strengthened our deterrence and defence in response to Russia's aggressive actions, while at the same time we remain open for a meaningful dialogue."
Leonid Slutsky, the chair of the foreign affairs committee in the lower house of the Russian parliament, dismissed the accusations against the diplomats as baseless and warned that Nato's move would further strain relations.
Mr Slutsky told the Interfax news agency Moscow could respond in retaliation, though he did not elaborate on his comments.
In 2018, Nato expelled Russian diplomats in response to a nerve agent attack in the city of Salisbury in the UK. It also reduced the size of Russia's mission from 30 to 20.