In this photo provided by the Ukrainian Presidential Press office, Ukrainian President Volodymyr Zelenskiy, left, speaks to relatives of Ukrainian prisoners waiting their arrival after being released after a prisoner exchange at Boryspil airport, outside Kyiv, Ukraine, Sunday, Dec. 29, 2019. Ukrainian forces and Russia-backed rebels in eastern Ukraine have exchanged 200 prisoners in a move aimed at ending their five-year war. The swap is part of an agreement brokered this month at a summit of the leaders of Ukraine, Russia, Germany and France. (Ukrainian Presidential Press Office via AP)