Maria Butina, who served nine months in a United States jail for acting as a Russian government agent, arrived in Moscow on Saturday, a day after her release from prison.

Butina arrived at Moscow's Sheremetyevo airport after leaving Miami, AFP journalists said. She had been held in Florida's Tallahassee prison.

In brief comments to journalists in the arrivals area of Moscow's Sheremetyevo airport on Saturday, Butina expressed "great thanks" to those who had supported her since her arrest in July 2018.

Butina, a former American University graduate student, was arrested in July 2018 on allegations of engaging in espionage. She pleaded guilty last December to conspiring to act as an unregistered agent for Russia. She admitted that she and a former Russian lawmaker worked to leverage contacts in the National Rifle Association to pursue back channels to American conservatives.

She was sentenced to 18 months in prison, half of which was credited as already served.