President Vladimir Putin has threatened U.S. media operating in Russia, saying Moscow would retaliate if U.S. officials put restrictions on Russian media in the United States.
The comments from Putin came October 19 during an appearance at a meeting of Russian and international foreign policy experts known as the Valdai Discussion Club, held in the Black Sea resort of Sochi.
Officials with Russian state-funded media, including the RT TV channel formerly known as Russia Today and the news website Sputnik, say those organizations' American units have been ordered to register under a decades-old law known as the Foreign Agents Registration Act.
The law was passed in the 1930s aimed at limiting the spread of Nazi propaganda in the United States.
Since a U.S. intelligence report in January accused RT and Sputnik of being part of a Russian campaign to meddle in the 2016 presidential election, a growing chorus of officials in Washington have called on those Russian media to comply with the law.
The Justice Department has not confirmed that it issued any order to RT or Sputnik.
Russian officials, meanwhile, have suggested they could restrict the work of some U.S. media in Russia, including CNN, Voice of America, and RFE/RL.
Putin echoed those remarks in his Valdai comments, though he did not specify what restrictions Moscow would take.
"In this case we will do it only in kind and quite quickly, as soon as we see steps [to pressure] our media, there will immediately be an answer," Putin said.
While RT distributes its programs freely in the United States on cable television, and Sputnik has an FM frequency in Washington, RFE/RL and Voice of America have no access to cable TV in Russia.
RFE/RL once had nearly 100 radio channels inside Russia, but had lost all of them by 2012.