The US Embassy is aware of reports that Russia's Federal Security Service (FSB) had opened an espionage case against a US citizen but had not received notifications from the Russian authorities and would be closely monitoring the situation, the US diplomatic mission in Moscow told RIA Novosti.

On Thursday, the FSB confirmed that it launched a criminal case against a US citizen under the article "espionage".

According to the FSB, the US citizen was suspected of collecting intelligence information on biological topics directed against the security of Russia.

"We are aware of unconfirmed reports of a case regarding a U.S. citizen in Russia," the US Embassy said.

"Generally, the Russian Federation does not abide by its obligations to provide timely notification of the detention of U.S. citizens in Russia," it told RIA Novosti.

The Embassy claimed that "Russian authorities also do not regularly inform the U.S. Embassy of the trials, sentencing, or movement of U.S. citizens detained in Russia."

"We have no further information to provide at this moment, but we are looking into the matter and will continue to monitor the situation closely," it concluded.

In the same context, White House Deputy Press Secretary Olivia Dalton said on Thursday that the Biden administration is still looking into reports about Russia opening a criminal case against a US national suspected of engaging in espionage, 

"We're still looking into it and nothing to share at this moment," Dalton indicated.

The incident echoed the case of former US Marine Paul Whelan who is currently serving a 16-year prison sentence in Russia after being found guilty of espionage.

Whelan was arrested in 2018 with a USB device containing sensitive information and was sentenced in 2020. Besides his US citizenship, he holds British, Canadian, and Irish passports.

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