He noted that Putin will escalate if he feels strong, pointing to Russian missiles crossing the airspace of NATO member states.
"There are cases in Poland, there are cases in Romania, and Russia is now entering other people's territorial waters and violating other people's airspace," Zelenskyy said.
"All this is recorded. This is a fact. These are the first steps, the first attempts. He will act like Hitler. You will see it. Because Putin has the same vision of the world."
Russian missiles and drones crossing the airspace of Poland and Romania
The Polish Armed Forces reported that a Russian missile entered Polish airspace at 5:23 a.m. Kyiv time near the town of Ocerdów in the Lubelskie Voivodeship on March 24, staying in the airspace for 39 seconds. The missile was tracked by Polish military radar systems throughout its flight.
Wreckage, likely from Russian drones used to attack Ukraine, has also been found several times in Romania.
NATO does not believe the attacks are deliberate. Romania has installed a system to counter drones on the border with Ukraine, and residents of border settlements receive alerts if there is a threat of falling debris.