Russia said on Tuesday it would retaliate over the U.S. expulsion of 12 of its diplomats at the United Nations for alleged spying.
Foreign Ministry spokeswoman Maria Zakharova said the U.S. action "will not remain without a proper reaction and an answer - not necessarily symmetrical."
The United States said on Monday the expelled diplomats were "intelligence operatives" who had been "engaging in espionage activities that are adverse to our national security."
(Reporting by Reuters in Moscow; Editing by Chris Reese)
