Russian court sentences American Ksenia Karelina, former ballerina, to 12 years for treason

Ksenia Karelina, an American-Russian citizen, plans to appeal, her lawyer said.

LONDON -- Ksenia Karelina, a dual American-Russian citizen, was sentenced Thursday to 12 years in a Russian penal colony on treason charges, local media reported.

Karelina was arrested in January and charged with treason, according to Russian state media and the court. She plans to appeal the verdict, her lawyer told ABC News on Thursday.

The prosecution had sought a 15-year prison sentence after Karelina entered a guilty plea, according to the court. The prosecution had also asked for a 2-year probation period and a fine of 500,000 Russian rubles, or about $5,600, according to the court.

The Sverdlovsk Regional Court had earlier extended her pre-trial detention in a jail in Yekaterinburg, Russia.

Investigators accused her of committing a crime under Article 275 of the Criminal Code of the Russian Federation. She was charged under that code with "high treason."

Mikhail Mushailov, a lawyer for Karelina, told ABC News at the time of her guilty plea that after the verdict he would seek her exchange, a move that Karelina had asked for.

The U.S. State Department was asked earlier this month about Karelina and other dual American citizens who were being held aboard. The question came as former U.S. Marine Paul Whelan, Wall Street Journal reporter Evan Gershkovich and Alsu Kurmasheva, a Russian-American journalist, were brought back to the United States through a mutli-country prisoner swap.

The U.S.'s message for those who were still detained was "pretty simple," Vedant Patel, a department spokesperson, told reporters during a press briefing. He added that "while today is a good day, that the work doesn’t stop."

"And to the American citizens who continue to be wrongfully detained or held hostage around the world, let me just be very clear that this government, this administration, is not going to stop working," Patel said.

ABC News' Joe Simonetti, Will Gretsky and Shannon K. Kingston contributed to this report.