He said this in an interview with AP, Ukrinform reports.
"Mariupol is the heart of this war today. It's beating. We're fighting. We're strong. And if it stops beating we will be in a weaker position. They [defenders of the city] are people who are distracting a big part of the enemy forces," Zelensky said.
He stressed that the stronger Ukraine's position in Mariupol, the stronger Ukraine's position in the east, in the area of the Joint Forces Operation, and as a result, the Ukrainian side will have advantages "in the dialogue with the Russian Federation."
"If our situation is weak in all these directions, then the talks will not happen because Russia will make all these steps which will lead to coming back to those cities which we liberated now. They may go for it. And our situation in talks will be weaker. And probably not even interesting for the Russian side," Zelensky said.
At the same time, he stressed that he believes in "another outcome and our victory."
Russian aggression caused one of the largest humanitarian catastrophes in Mariupol. The invaders have been bombing unarmed residents and blocking humanitarian aid. According to Mariupol Mayor Vadym Boichenko, the number of civilian casualties in Mariupol is about 5,000, including about 210 children.
