Ukrainian President Volodymyr Zelenskiy was referring to imposing sanctions on Russia when he suggested preventive strikes were necessary to preclude any use of nuclear weapons, his spokesperson said.

Russian Foreign Minister Sergei Lavrov said the remarks, made by Zelenskiy during a discussion with an Australian think tank on Thursday, confirmed the need for what Moscow calls its "special operation" in Ukraine.

"Colleagues, you have gone a little too far with your nuclear hysteria and now you hear nuclear strikes even where there are none," Zelenskiy's spokesperson, Serhii Nykyforov, wrote on Facebook.

"The President spoke about the period until (Russia's invasion of Ukraine on) February 24. Then it was necessary to apply preventive measures to prevent Russia from starting the war. Let me remind you that the only measures that were about then were preventive sanctions."

Nykyforov said hints at the use of nuclear weapons were "afforded only by the terrorist state Russia. You will never hear such calls from Ukraine." (Reporting by Kyiv newsroom, Editing by Timothy Heritage)