The service said in a press release that an American national, Paul Whelan, was detained as part of a special operation.
The Federal Security Service, or FSB, the top KGB successor agency, said Paul Whelan was detained in Moscow on Friday.
The move is largely seen as retribution for the U.S. arrest and conviction of Russian national Maria Butina for espionage. "We have requested this access and expect Russian authorities to provide it". The charges he faces could carry a prison term of as much as 20 years, according to Russia's criminal code.
The arrest comes days after Russian citizen Maria Butina pleaded guilty to conspiring to act as a secret foreign agent in the United States.
US citizen detained in Moscow on suspicion of espionage - FSB
The Kremlin has denied that Butina is a Russian agent and has organized a social-media campaign to secure her release. Butina said in court that she'd been operating as a Kremlin agent as she befriended National Rifle Association leaders and influential USA conservatives.
In the past, Russian Federation has arrested foreigners with the aim of trading prisoners with other countries.
The Russian Foreign Ministry said the U.S. Embassy was duly notified about the arrest, but wouldn't give any further information.
That arrest was made at the behest of the United States, which is seeking the extradition of the executive, Meng Wanzhou, in relation to violations of US sanctions on Iran.