According to him, the incident taught the Ukrainians two things.
"The first is that the state should always speak frankly with people ... The second is that by rallying and uniting, people are able to curb and stop any calamity," Zelensky wrote.
The elected leader also noted that the country "does not have the right to forget these lessons in order to prevent this from happening in the future."
"I bow my head before the heroes of the liquidators," he concluded.
April 26 marks the 33rd anniversary of the tragedy at the Chernobyl nuclear power plant, where in 1986 there was the largest catastrophe in the history of nuclear energy.
According to official information, 31 people died in the first three months after the explosion.