Police officers stop young activists trying to protest outside Kiev's Mariinsky Palace on May 20, 2020 during Ukraine's President Zelensky's press conference marking his first presidency term. (Photo by Sergei SUPINSKY / AFP)

Police officers stop young activists trying to protest outside Kiev's Mariinsky Palace on May 20, 2020 during Ukraine's President Zelensky's press conference marking his first presidency term. (Photo by Sergei SUPINSKY / AFP)

Activists protest outside Kiev's Mariinsky Palace on May 20, 2020 during Ukraine's President Zelensky's press conference marking first year in office. (Photo by Sergei SUPINSKY / AFP)

Police officers block a park outside Kiev's Mariinsky Palace on May 20, 2020 during Ukraine's President Zelensky's press conference marking first year in office. (Photo by Sergei SUPINSKY / AFP)

Activists of National Corps far-right party hold a banner reading "Yermak fuck off" and burn flares during their protest action demanding resignation of Andriy Yermak, chief of Zelensky's staff, outside Kiev's Mariinsky Palace on May 20, 2020 during Ukraine's President Zelensky's press conference marking first year in office. (Photo by Sergei SUPINSKY / AFP)

Activists of National Corps far-right party hold a banner reading "Yermak fuck off" and burn flares during their protest action demanding resignation of Andriy Yermak, chief of Zelensky's staff, outside Kiev's Mariinsky Palace on May 20, 2020 during Ukraine's President Zelensky's press conference marking first year in office. (Photo by Sergei SUPINSKY / AFP)

Activists of National Corps far-right party hold a banner reading "Yermak fuck off" during their protest action demanding resignation of Andriy Yermak, chief of Zelensky's staff, outside Kiev's Mariinsky Palace on May 20, 2020 during Ukraine's President Zelensky's press conference marking first year in office. (Photo by Sergei SUPINSKY / AFP)

Activists of National Corps far-right party hold a banner reading "Yermak fuck off" during their protest action demanding resignation of Andriy Yermak, chief of Zelensky's staff, outside Kiev's Mariinsky Palace on May 20, 2020 during Ukraine's President Zelensky's press conference marking first year in office. (Photo by Sergei SUPINSKY / AFP)

Activists of National Corps far-right party hold a banner reading "Yermak fuck off" during their protest action demanding resignation of Andriy Yermak, chief of Zelensky's staff, outside Kiev's Mariinsky Palace on May 20, 2020 during Ukraine's President Zelensky's press conference marking first year in office. (Photo by Sergei SUPINSKY / AFP)

Activists of National Corps far-right party burn flares during their protest action demanding resignation of Andriy Yermak, chief of Zelensky's staff, outside Kiev's Mariinsky Palace on May 20, 2020 during Ukraine's President Zelensky's press conference marking first year in office. (Photo by Sergei SUPINSKY / AFP)

Activists of National Corps far-right party hold a banner reading "Yermak fuck off" during their protest action demanding resignation of Andriy Yermak, chief of Zelensky's staff, outside Kiev's Mariinsky Palace on May 20, 2020 during Ukraine's President Zelensky's press conference marking first year in office. (Photo by Sergei SUPINSKY / AFP)

Activists of National Corps far-right party hold a banner reading "Yermak fuck off" during their protest action demanding resignation of Andriy Yermak, chief of Zelensky's staff, outside Kiev's Mariinsky Palace on May 20, 2020 during Ukraine's President Zelensky's press conference marking first year in office. (Photo by Sergei SUPINSKY / AFP)