Russia on Friday called on the U.S. embassy in Moscow to waive the diplomatic immunity of three of its staff, saying they were suspected of stealing.
The announcement comes amid simmering tensions between Moscow and the West and days after NATO stripped eight members of the Russian mission to the alliance of their accreditation.
Russia's Foreign Ministry said it sent a note to the embassy with the request to "waive the diplomatic immunity of three employees of the U.S. mission in order to prosecute them on criminal charges."
It added that the three employees were "stealing the personal items of a Russian citizen."
In its statement, the ministry said that if their request was denied, the diplomats should "immediately" leave Russia.
Earlier on Friday, the press service of Moscow's Interior Ministry told the TASS news agency that it received a complaint over a stolen backpack.
The ministry's spokesman Vladimir Vasenin said that servicemen of the U.S. Marine Corps, aged 21 to 26, were caught on CCTV footage.
He added that the incident resulted in damage worth 15,000 rubles ($200).
A criminal case has been launched over theft, charges that carry a maximum penalty of five years in jail.
A source told the Interfax news agency that the incident took place in a Moscow bar on Sept. 18 and the U.S. citizens were "inebriated."
Tensions are high between Moscow and Washington over a range of issues, including claims of meddling in U.S. elections and Russia's human rights record.
This year Russia formally designated the United States an "unfriendly" state, barring its embassy from employing Russian nationals.
In June, U.S. President Joe Biden and Russian counterpart Vladimir Putin met in a high-profile summit at which they agreed it was vital to keep talking despite the differences that divide them.