The Ukrainian leader said this on his Twitter account, Ukrinform reports.
"Had a call with Czech President Petr Pavel. Congratulated him on officially taking office. Outlined the situation at the front & our security needs. We discussed Ukraine's EU integration & agreed to further cooperate," Zelensky said.
He said that Czech support is crucial for Ukraine in fighting Russia's aggression.
Pavel officially took office as president of the Czech Republic on March 9.
Pavel was elected Czech president on January 28.