"We will act to protect our people: both in the Kherson region, in the Zaporizhzhia region, in the Donbas, in the currently occupied areas of the Kharkiv region, and in the Crimea," he said in a video posted on Telegram.

"This farce in the occupied territory cannot even be called an imitation of referendums," he said.

Officials in four Moscow-occupied regions of Ukraine claimed victory in the referendums, slammed as sham ballots by Kyiv and its Western allies.

Earlier, Zelensky told the United Nations that Ukraine would not be able to negotiate with Russia after the votes.

"Russia's recognition of the pseudo-referendums as 'normal', implementation of the so-called Crimean scenario, and yet another attempt to annex Ukrainian territory means that there is nothing to talk about with (the) current Russian president," he said in a video message at a meeting of the UN security council.

"In front of the eyes of the whole world, Russia is conducting an outright farce called a 'referendum' on the occupied territory of Ukraine," he said.

"People are forced to fill out some papers for a TV picture under the muzzles of machine guns.

"The figures of the alleged results of the pseudo-referendum were drawn in advance," he said.