On Wednesday, Zelenskyy said Trump is living in a disinformation space.
In a social media post Tuesday, Trump called Zelenskyy a "dictator without elections."
And, he said the Ukrainian president needs to move quickly to negotiate an end to the war with Russia or risk not having a country to lead.
Trump is trying to negotiate a deal to end the fighting. Ukraine says the terms are too favorable to Russia.
There is strong reaction in the Ukrainian community.
"We just feel betrayed, most Ukrainians here in the United States," Ukrainian American Roman Panychevnyy said.
Pannychevnyy said the cost of this war is felt by all Ukrainians.
RELATED: Chicago Ukrainians skeptical Russia, Ukraine moving toward peace after Trump-Putin call
"My friend from school died last week. Probably every Ukrainian family has someone who was on the front line and died," Panychevnyy said.
The manager and host at Radio UA Chicago, Dmytro Halan, said many Ukrainians who could vote voted for Trump on his promise of ending the war.
"It's difficult because we lost a lot of people," Halan said. "I think we need to work together with the United States. Because, without the United States, it will be extremely hard to fight back."
On Tuesday, Trump made the false allegation that Ukraine started the war.
"Well, you been there for three years. You should have ended it three years. You should have never started it. You could have made a deal," Trump said.
Russian troops invaded Ukraine on Feb. 24, 2022.
"Literally, it's not true that Ukraine attacked Russia. It's not true that Ukraine was the aggressor," University of Chicago professor Konstantin Sonin said.
Sonin is a Russian living in exile, and was sentenced in absentia for being critical of the Russian government.
"It's kind of disheartening because countries around the world look at the United States as an example," Sonin said. "There is some goodness in being the leader of the democratic world. So, as setting an example, this is not good."