"Taking into account the preliminary results of the referendums and Russia's readiness to acknowledge them, the accession of the territories is likely to take place as early as on September 30," the unnamed member of Russia's State Duma said to TASS.

Voting is set to conclude Tuesday in Donestk, Luhansk and the Kherson and Zaporizhzhia regions, meaning as early as Wednesday or even Thursday announcements of results are likely to trickle out, paving the way for a potential Friday official declaration.

While Russian forces do not yet control the entirety of each of these territories, their annexation would constitute Ukraine losing almost 20% of its geographic territory.

Russian President Vladimir Putin might himself make the proclamation following the referendums, which Ukrainian leaders along with Washington have dismissed as a "sham" - saying they won't be recognized. Russian media reports indicate:

The lawmaker said Russian President Vladimir Putin could take part in the procedure on September 30. "I don't know if he will [participate], but he is likely to do so," the MP said.