A woman walks past a giant electoral poster of Ukrainian President Petro Poroshenko displayed on a building in central Kiev on March 22, 2019, ahead of Ukraine's presidential elections. - Ukraine is to hold presidential elections on March 31, 2019. (Photo by Sergei SUPINSKY / AFP)

Passersby walk past a giant electoral poster of Ukrainian President Petro Poroshenko displayed on a building in central Kiev on March 22, 2019, ahead of Ukraine's presidential elections. (Photo by Sergei SUPINSKY / AFP)