The Russian Foreign Ministry is to expel four American Embassy officials for activities "incompatible with diplomatic status", a euphemism for espionage.
The US deputy chief of mission, John Ordway, was called to the ministry in connection with the announced expulsion of 50 Russian diplomats from Washington, the ministry press service said.
A US Embassy official declined to comment.
The ministry also said it would take other measures to stop American officials' "unlawful activities" in Russia, it was reported.