Belarus has “unilaterally” freed an American woman from detention, U.S. Secretary of State Marco Rubio announced Sunday, as the Kremlin-allied country held an orchestrated election poised to give strongman President Alexander Lukashenko yet another term on top of his three decades in power.

Rubio’s post on the X social network identified the U.S. citizen as Anastassia Nuhfer. It said she was detained during former President Joe Biden’s tenure, but did not specify when or why.

Rubio’s statement came following waves of prisoner releases by Lukashenko, often dubbed “Europe’s last dictator.” Belarus’ oldest rights group, Viasna, says that over 1,250 people remain in detention over their opposition to the authorities.

Lukashenko’s opponents, many of whom are imprisoned or exiled abroad by his unrelenting crackdown on dissent and free speech, have called Sunday’s election a sham. The last election in 2020 triggered months of mass protests unprecedented in Belarusian history.

The U.S. State Department said later on Sunday that Nuhfer was detained in early December 2024. It said that earlier this month, a consular officer from Washington was granted rare access to an American detainee in Belarus.

A former high-ranking Belarusian diplomat told AP that Nuhfer’s arrest was linked to the 2020 protests, although he did not give details. The source, who spoke on condition of anonymity due to security concerns, said that Lukashenko himself offered to free the U.S. citizen “as a gesture of goodwill,” while declining to release any Belarusian opposition and rights activists.

Nuhfer’s release took the public and even Belarusian activists by surprise. Her name hadn’t been publicly released and hadn’t featured on lists of political prisoners.

Pavel Sapelka of the Viasna rights group, said that he and his colleagues had been unaware of her arrest or its circumstances.

Lukashenko’s support for the war in Ukraine has led to the rupture of Belarus’ ties with the U.S. and the EU, ending his gamesmanship of using the West to try to win more subsidies from the Kremlin.

But Artyom Shraybman, a Belarus expert with the Carnegie Russia and Eurasia Center, predicted that Minsk could try to ease its total dependence on Russia after the election, by again seeking to reach out to the West.

“Lukashenko’s interim goal is to use the election to confirm his legitimacy and try to overcome his isolation in order to at least start a conversation with the West about easing sanctions,” Shraybman said.

It was unclear what, if any, concessions Minsk has requested in exchange for releasing the U.S. citizen.