"If the occupiers proceed along the path of pseudo-referendums they will close for themselves any chance of talks with Ukraine and the free world, which the Russian side will clearly need at some point," Zelenskiy said in his nightly video address.

Russian and Ukrainian officials held several sessions of talks soon after Russian forces launched their invasion of Ukraine. But no meetings have been held since late March, with each side blaming the other for the halt to contacts.

(Reporting by Ronald Popeski; Editing by Chizu Nomiyama)