The Russian FSB State Security agency claims that it has arrested a United States citizen named Paul Whelan who was "caught spying" in Moscow.
According to BBC, the U.S. Department of State confirmed that Moscow notified them of the alleged arrest, but did not confirm the arrest or the man's name.
According to Reuters, the man was allegedly arrested on December 28th, but neither the United States nor Russia have commented on the nature of his alleged spying activity. The State Department has requested consular access to see the American citizen. A spokesperson told Reuters, "We have requested this access and expect Russian authorities to provide it."
Russian authorities indicated that they had opened a criminal case against the alleged spy, which could carry penalties of 10 to 20 years in prison.
Public accusations of spying have become more commonplace in recent years, as relations between the United States, the United Kingdom, and Russia have deteriorated since the Russian invasion of Crimea in 2014.
American authorities detained and charged Russian national Maria Butina with spying earlier this year. Butina pled guilty last week to a conspiracy charge, but Russian President Vladimir Putin denounced the charges as a "lie," saying, "I don't understand what they jailed her for. There are no grounds."
Likewise, the British government has been involved in a slowly-escalating war of accusations concerning the apparent poisoning of former Russian agent Sergei Skripal on British soil.