"Together we pay tribute to all the innocent victims of Volhynia!
Memory unites us!," Duda's office and Zelenskiy both wrote on Twitter.
The Ukrainian president's chief of staff, Andriy Yermak, wrote on Telegram that Ukraine and Poland were "united against a common enemy who dreamed of dividing us".
"We agreed to work together to get the best possible result for Ukraine," Zelenskiy wrote.
However, Ukraine's parliament speaker Ruslan Stefanchuk moved to defuse tensions in May when he told the Polish parliament that Kyiv understood Poland's pain.
Persons:
Kyiv's staunchest, Ukraine's Volodymyr Zelenskiy, Andrzej Duda, Zelenskiy, Stanislaw Gadecki, Andriy Yermak, Duda, Pawel Szrot, Stepan Bandera, Ruslan Stefanchuk, Max Hunder, Alan Charlish, William Maclean, Sharon Singleton
Organizations:
Twitter, Polish Bishop's Conference, NATO, Polsat, Ukrainian Insurgent Army, Organization of Ukrainian Nationalists, Kyiv, Thomson
Locations:
Ukrainian, Warsaw, Russia, Volhynia, Lutsk, Ukraine, Poland, Vilnius, Kyiv