The U.S. and Russia announced they have carried out another prisoner swap — the second such exchange since Donald Trump returned to the White House vowing to improve relations with the Kremlin and end the war in Ukraine.

According to the deal negotiated by the countries’ intelligence agencies, Russia released Ksenia Karelina, a dual Russian and American citizen who had been serving out a 12-year sentence in a maximum security prison colony.

A native of Russia’s Ural mountains who later moved to Los Angeles, the 33-year-old ballet dancer was detained while visiting her parents in Russia in February of last year.

The reason: Karelina had donated just over $50 to a U.S.-based Ukrainian aid charity, on February 24, 2022, the day Russia launched its full-scale invasion of Ukraine. Prosecutors accused her of financing the Ukrainian army, a charge for which she was later convicted of treason.

Under the exchange, the U.S. had freed Arthur Petrov, a dual Russian-German citizen accused of illegally exporting military grade electronics in violation of U.S. sanctions on Russia over its actions in Ukraine.