Ukraine’s president Volodymyr Zelensky warned that Russia could use nuclear weapons to try and force a victory.

“I think all of the world, all the countries have to be worried,” he told CNN. “They could do it. For them the lives of the people are nothing.”

The threat of Russia potentially using tactical or low-yield nuclear weapons in Ukraine cannot be taken lightly, CIA Director William Burns said on Thursday.

Mr Zelensky told the Atlantic he was tired of repeating himself in phone calls with world leaders.

“When some leaders ask me what weapons I need, I need a moment to calm myself, because I already told them the week before. It’s Groundhog Day. I feel like Bill Murray.”

Real victory, he said, will come only when the perpetrators are tried, convicted, and sentenced.

“My daughter is almost 18. I don’t want to imagine, but if something had happened to my daughter, I would not have been satisfied if the attack had been repelled and the soldiers had run away,” he said. “I would have looked for these people and I would have found them. And then I would feel victory.”

Mr Zelensky has also reportedly asked Mr Biden to designate Russia a “state sponsor of terrorism”, according to the Washington Post. The US’ list of such countries currently includes just four states: North Korea, Cuba, Iran and Syria.