Russian prosecutors are considering a retaliatory response following Washington’s request that the RT America news channel register as a foreign agent.

The Prosecutor General’s Office is studying the possibility of labeling U.S. media outlets “undesirable,” the Interfax news agency reported Friday, citing an unidentified source knowledgeable of the situation.

Amid concerns over Russian meddling in the 2016 presidential elections, the U.S. Justice Department has requested that the Kremlin-backed RT adhere to a 1930s foreign agent registration law.

Russian Foreign Ministry spokeswoman Maria Zakharova has said that “every step toward the Russian media will have a corresponding response.”

The Russian authorities are considering blacklisting U.S. media at the Federation Council committee on state sovereignty’s task force session, according to Interfax.

“This could affect all American media operating in Russia,” Interfax reported, citing an unidentified source. The outlets being considered for the “undesirable” label were not disclosed.

Kremlin spokesman Dmitry Peskov told reporters on Friday that reciprocal actions cannot be ruled out, but noted that he had no information regarding U.S. outlets being labeled “undesirable,” state-run news agency RIA Novosti reported.

The Interfax report comes a week after Russia’s state media censor Roskomnadzor warned CNN International over alleged media law violations.