The world premiere of Mstislav Chernov's documentary 20 Days in Mariupol took place at the Sundance Film Festival. In the nomination of the World Cinema Documentary Competition, the film will compete with 11 other documentaries.

Chernov's work became part of a joint project by PBS Frontline and the Associated Press, which investigates the topic of victims of Russian aggression in Ukraine. An Associated Press camera crew Mstislav Chernov, Yevhen Maloletka and Vasilisa Stepanenko arrived in Mariupol on February 24 last year, hours before the full-scale Russian invasion began. For twenty days, journalists recorded the events in Mariupol: shelling, bombing and the death of civilians.

As Mstislav Chernov told Suspilne, it was possible to take about 30 hours of video out of the city. Later, the studio PBS Fronline joined the creation of the documentary.