WASHINGTON (Sputnik) - Russian citizen Maria Butina, who is serving an 18-month prison term on charges of conspiring to act as a foreign agent in the United States, has appealed her case, but it is unlikely the appeal will be completed before her release from prison, Butina's lawyer Robert Driscoll told Sputnik.

"The appeal process is moving, [but] the appeals court has yet to set a briefing schedule", Driscoll said. "It is unlikely that the appeal will be heard or decided prior to Maria’s departure".

According to the Federal Bureau of Prisons (BOP), Butina is eligible for release on 25 October. The BOP had said earlier Butina could be released on 5 November.

She will have served nearly 16 months in US prison by the time of her release, after having been arrested on 15 July 2018.

© REUTERS / Alexandria Sheriff's Office Maria Butina appears in a police booking photograph released by the Alexandria Sheriff's Office

On 26 April a US federal judge sentenced Butina to 18 months in prison after she pleaded guilty to a single count of conspiring to act as an unregistered foreign agent. Butina, who signed the plea deal after being held for prolonged periods in solitary confinement, had requested a sentence of time served.

The Russian Foreign Ministry has called Butina's sentence a disgrace to the US judicial system and has accused the court of carrying out a political order. Russian President Vladimir Putin said Butina’s indictment is unjustified because she was not tasked to perform any mission on behalf of the Russian government.

Butina is serving her term in the federal prison in Tallahassee, Florida.