Ukrainian President Volodymyr Zelenskyy on Thursday asked artists and filmmakers to unequivocally declare their support for his country during a live video address at the opening of the 73rd Berlin International Film Festival.

Referring to the Berlin Wall which divided the German capital from 1961 to 1989 into the capitalist west and communist east, Zelenskyy said that now Russia, which attacked Ukraine almost one year ago, is building a new — figurative — wall in his country.

“This is a wall between freedom and slavery,” Zelenskyy said adding that the art world cannot remain indifferent because amid silence the “voice of evil only becomes louder and more convincing.”

Zelenskyy, a former comedian and actor, features prominently in Sean Penn’s film about the war in Ukraine, “Superpower,” which will have its world premiere at the Berlinale.

Before the opening ceremony, U.S. actress Anne Hathaway lauded the Ukrainian president as a “hero of our time” and thanked the festival for inviting him via video link, German news agency dpa reported.

Germany’s minister of culture also stressed the importance of culture in times of war and crisis. “Whoever makes films and whoever shows films in dark times resists bondage,” Claudia Roth said.

This year’s film festival, which runs until Feb. 26, will see 18 films compete for the Golden and the Silver Bear awards. The winners will be chosen by a jury headed by American actor, screenwriter and director Kristen Stewart.

The festival was set to open with the premiere of Rebecca Miller’s “She Came to Me,” starring Hathaway, Marisa Tomei and Peter Dinklage.