Moscow on December 6 accused U.S. intelligence services of trying to recruit Russian journalists working in the United States.
"Recently Russian journalists, including those in the United States, have come under great pressure from the special services, notably through attempts at recruitment," Russian news agencies quoted Russian Foreign Ministry Spokeswoman Maria Zakharova as saying.
"This is an aggression. An aggression in terms of intelligence not only towards Russia, but also an encroachment on freedom of expression throughout the world," she was quoted as saying.
Zakharova claimed that one Russian journalist in the United States, who she did not name, was pressured to cooperate with U.S. intelligence agencies through bribes and psychological tactics.
When those did not work, she said U.S. agents directly threatened the journalist and tried to contact his family.
Her accusations came the same day Russian lawmakers voted to ban U.S. media that Moscow has labelled as "foreign agents" from entering the lower house of parliament.
The ban was a reaction to a recent move by the U.S. Congressional Press Gallery to strip Russian state-controlled television network RT of its credentials.
The Russian Foreign Ministry's website said there are around 20 American media outlets accredited to work in Russia, including Voice of America, Radio Free Europe/Radio Liberty, and RFE/RL affiliated services.
Those branded "foreign agents" have to present themselves as such on all paperwork and submit to intense scrutiny of their staffing and finances.