President of Ukraine Volodymyr Zelensky is confident that humanitarian supplies from the Ukrainian side are not allowed into Mariupol because the Russian side is afraid that "the world will see what is happening there."

"They are all afraid that the world will see what is there. Therefore, we cannot bring in humanitarian supplies. There are not dozens, but thousands of dead, thousands of wounded," he said on Wednesday in an interview with the Turkish Haberturk TV channel.

"We do not know how many Mariupol residents ended this life tragically. But they can't hide it. It's thousands of people, it's impossible to do. We will see this when we can enter our city," the President believes.

Answering a question about responsibility for crimes against civilians, Zelensky said: "The Russian army and political leadership, everyone who developed this operation, gave orders and carried them out – all are war criminals. Everyone must be held accountable."