MOSCOW (Reuters) - Russia said on Saturday it had expelled two U.S. Embassy staff members in June after a similar 'unfriendly' move by Washington.

One of the expelled diplomats was involved in an incident with a Russian policeman near the U.S. Embassy entrance in Moscow, the Foreign Ministry said in a statement, citing Deputy Foreign Minister Sergei Ryabkov.

Another diplomat was "also a CIA operative", Ryabkov said.

Relations between Russia and the United States have chilled following Russia's annexation of the Crimean peninsula from Ukraine in 2014, after which the West imposed sanctions against Russia.

Ryabkov said the two U.S. diplomats were declared persona non grata.

"We hope that they in Washington will realize all the viciousness of the aggressive anti-Russia line. If they decide there to move on the path of escalation, they won't be left without a response," the statement cited Ryabkov as saying.

The United States expelled two Russian officials on June 17 in response to an attack by a Russian policeman on a U.S. diplomat in Moscow earlier in the month, the State Department said on Friday.

(Reporting by Vladimir Soldatkin; Editing by Janet Lawrence)