For Ukraine, the issue of territorial integrity and sovereignty is fundamental, Andriy Yermak, the head of the President's Office of Ukraine, said.

"Any fake referendums in ORDLO on joining the Russian Federation will not be recognized by Ukraine and the world. And attempts by Russians to raise the stakes in this way, to undermine Ukrainian sovereignty will still not be successful. For Ukraine, the issue of territorial integrity and sovereignty is a matter of principle," Yermak wrote in Telegram channel on Sunday.

Earlier, leader of the so-called LPR Leonid Pasechnik announced the intention to hold a referendum on joining the Russian Federation in the occupied territories of Luhansk region.