NATO said Wednesday it expelled eight members of Russia's mission to the military alliance for allegedly working in secret as intelligence officers.
"We can confirm that we have withdrawn the accreditation of eight members of the Russian Mission to NATO, who were undeclared Russian intelligence officers," an unnamed NATO official said.
NATO also said it would cut the number of positions that Russia could accredit to NATO from 20 to 10 at the end of October. The alliance did not immediately explain why the decision was made.
The official said, "NATO's policy towards Russia remains consistent. We have strengthened our deterrence and defense in response to Russia's aggressive actions, while at the same time we remain open for a meaningful dialogue."
Senior Russian lawmaker Leonid Slutsky, head of the Russian lower house of parliament's international affairs committee, said Moscow would retaliate but did not provide specifics, according to Interfax.
NATO-Russian relations have steadily deteriorated since Moscow annexed Ukraine's Crimean Peninsula in 2014. NATO and Russia also disagree over issues such as Russia's nuclear missile development and aerial intrusions into NATO airspace.
Some information for this report came from the Associated Press and Reuters.