"Regarding the issue of strengthening NATO's eastern flank, if this is about increasing alliance forces in Poland, the political scene agrees that this is a correct decision and is essential," Duda said, as quoted by the Telewizja Republika broadcaster.
The summit is expected to be the largest ever summit of the alliance as the Polish capital expects to host more than 2,000 people, including 26 delegations from NATO partners and observers.
NATO has been reinforcing its military presence in Europe, particularly in Eastern European states, since the outbreak of the Ukrainian crisis, citing Russia's alleged interference in that conflict as justification for the move. Moscow has repeatedly denied the accusations, calling NATO's military buildup near Russia’s borders provocative.