Klitschko, a heavyweight boxing champion, has – along with his brother Vitali – become a prominent figure in the Ukraine protests calling for closer ties with the European Union. Vitali serves in the Ukrainian parliament, and has announced his intention to run for the presidency in 2015.
Pro-Europe demonstrations in Kiev reached a fever pitch after President Viktor Yanukovych decided to abandon a trade deal with the EU on Nov. 21 in favor of pursuing closer ties with Moscow.
Since then, protesters have blockaded the main government headquarters and are occupying government buildings in Kiev.
"Your fight is not falling on deaf ears," Panettiere told an assembled crowd. "The world will hear you. And as an American I want you to know that I stand by you, I support your fight, and I will support it until the country of Ukraine in its entirety reflects the beauty, the true beauty of Ukrainian people," the Nashville star said as Klitschko translated. "Keep fighting. I love you all."