Russian prosecutors on August 8 asked for a 15-year prison sentence for Ksenia Karelina, a dual U.S.-Russian citizen who has been held in Russia since January, Russian news agencies reported.
"The prosecution has demanded 15 years in a general penitentiary," lawyer Mikhail Mushailov was quoted by Russian media as telling reporters.
Mushailov on August 7 told the media that Karelina, 33, pleaded guilty to a charge of treason.
Karelina was not included in the major prisoner swap between Russia and the West on August 1 that saw three Americans released from Russian custody.
She has been on trial in the city of Yekaterinburg over a 2022 donation to a charity supporting Ukraine.
Karelina was detained by Russia's Federal Security Service in January in Yekaterinburg, where she had traveled to meet relatives.
A resident of Los Angeles and U.S. citizen since 2021, Karelina was initially charged with hooliganism, reportedly for cursing at police officers.
Security agents, however, searched her phone and said they discovered that prior to traveling to Russia she had made a $51 donation to a U.S-based organization that provides aid and assistance to Ukraine.
The August 1 prisoner swap involving the United States, Russia, and several European countries included three high-profile U.S. citizens, as well as five German citizens jailed in Russia and Belarus and eight Russian political activists held in Russia in connection with their opposition to President Vladimir Putin.
But Karelina and several other Americans whom Washington has designated as unjustly imprisoned and hundreds of Russian citizens seen as political prisoners remain behind bars in Russia, prompting calls for Western governments to vigorously pursue their release as well.
"They remain in torturous conditions. They are in grave danger. We simply must not forget about them, even against the euphoric backdrop that it was possible to pull someone out," Russian opposition politician in exile Dmitry Gudkov told Current Time after the prisoner swap, which saw eight Russians -- including a convicted assassin and spies -- returned to Moscow from Western custody.