Zelensky warns that Russia could use nuclear weapons: 'For them, life of the people is nothing'

Ukrainian President Volodymyr Zelensky remained committed to not giving up parts of his country to Russia in exchange for peace and warned that nations across the world should be "worried" about the possibility of Russian President Vladimir Putin detonating a nuclear or chemical weapon.

"I think, all over the world, all the countries have to be worried," Zelensky told CNN's Jake Tapper during an interview published Sunday about the possibility of Russia using a nuclear or chemical weapon. He also stressed that there is abundant Russian disinformation on the matter.

"There is a possibility of them using these weapons. Nobody expected there to be a full-scale invasion of Ukraine from the Russian Federation. No one expected there to be a war in 2014. And now that there will be a full-scale invasion and killing of civilians, nobody expected them to invade the areas where there's no military equipment and just kill and shoot dead a civilian population," he said.

"For them, life of the people is nothing," Zelensky said. "That's why we should... not be afraid. Be ready."

Tapper also asked Zelensky about giving Donbas in eastern Ukraine to Russia in an effort to stop the invasion.

"Ukraine and the people of our state are absolutely clear. We don't want anyone else's territory, and we are not going to give up our own," Zelensky said. He remains optimistic that Ukraine will win the war against Russia.

However, the situation in the besieged port city of Mariupol is getting worse, Zelensky said.

A United Nations report last week said that residents of Mariupol are being "starved to death."

"It's clear that things won't get better," Zelensky said, explaining that while an estimated 10,000 civilian have died there, casualties are unclear due to the number of people evacuated by Russian forces without a "document trail." 

Turning the conversation more personal, Tapper asked Zelensky how he wants to be remembered by the Ukrainian people.

"A human being that loved life to the fullest and loved his family and loved his motherland, definitely not a hero. I want people to take me as I am, a regular human," the president responded, adding that his heroes are the Ukrainian people.