The Kremlin on Thursday blasted NATO's decision to strip eight Russian diplomats of their accreditation at the military alliance's headquarters in Brussels.
NATO said on Wednesday it was withdrawing their accreditation because they were secretly working as intelligence officers.
The maximum staff levels of Moscow's NATO delegation was also halved, from 20 to 10.
Kremlin spokesperson Dmitry Peskov said NATO's actions showed that it was not serious about wanting to improve relations.
"These actions do not allow us to have illusions about a possible normalization of relations and resumption of dialogue with NATO," he said. "On the contrary, these prospects are practically completely destroyed," he was quoted by the Interfax news agency as saying.
At a press conference on Thursday, NATO Secretary-General Jens Stoltenberg would not elaborate on the nature of the Russian activity, but said the decision against the eight envoys was not due to "any particular event" in a NATO member country.
Rather, "we have seen over some time now an increase in Russian malign activity and therefore we need to be vigilant and of course we need to act when we see members of the Russian delegation to NATO conducting activity that are not in line with their accreditation," he said.
Stoltenberg stressed that, despite the incident, NATO wanted to maintain dialogue with Moscow.
The alliance made a similar move back in 2018, expelling seven diplomats in response to a nerve agent attack in Britain on former Russian spy Sergei Skripal and his daughter.
