Ukrainian President Volodymyr Zelenskiy (L) greets his Polish counterpart Andrzej Duda in Kiev, on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (L) and Polish President Andrzej Duda bump fists as they meet in Kiev, on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (L) greets his Polish counterpart Andrzej Duda in Kiev, on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (L) greets his Polish counterpart Andrzej Duda in Kiev, on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (L) greets his Polish counterpart Andrzej Duda in Kiev, on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Polish President Andrzej Duda, his wife Agata Kornhauser-Duda (L), Ukrainian President Volodymyr Zelensky and his wife Olena Zelenska stand during a welcome ceremony in Kiev, on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (L) and Polish President Andrzej Duda review a guard of honour during a welcoming ceremony ahead of their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (L) and Polish President Andrzej Duda review a guard of honour during a welcoming ceremony ahead of their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (L) and Polish President Andrzej Duda review a guard of honour during a welcoming ceremony ahead of their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (L) and Polish President Andrzej Duda review a guard of honour during a welcoming ceremony ahead of their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (3rd R) and and his wife Olena (2nd R), and Polish President Andrzej Duda (3rd L) and his wife Agata Kornhauser-Duda (2nd L) stand during a welcoming ceremony ahead of their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (C-R) and Polish President Andrzej Duda (C-L) stand during a welcoming ceremony ahead of their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (2nd R) and Polish President Andrzej Duda (2nd L) take part in a signing ceremony during their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (R) and Polish President Andrzej Duda (L) take part in a signing ceremony during their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (R) and Polish President Andrzej Duda (L) hold a press briefing during their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (R) and Polish President Andrzej Duda (L) hold a press briefing during their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (R) and Polish President Andrzej Duda fist bump during a joint sigging ceremony as part of their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (R) and Polish President Andrzej Duda (L) arrive for a joint sigging ceremony as part of their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Polish President Andrzej Duda holds a joint news briefing with his Ukrainian counterpart as part of their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Ukrainian President Volodymyr Zelensky (R) and Polish President Andrzej Duda (L) hold a joint news briefing as part of their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)

Head of Polish Oil Mining and Gas Extraction Company (PGNiG) Jerzy Kwiecinski (2nd L) and head of Ukraine's State Property Fund Dmytro Sennychenko (2nd R) fist bump, flanked by Ukrainian President Volodymyr Zelensky (R) and Polish President Andrzej Duda (L), during a joint singing ceremony as part of their meeting in Kiev on October 12, 2020. (Photo by VALENTYN OGIRENKO / POOL / AFP)