Russian President Vladimir Putin on Friday signed the document to formally annex four Ukrainian provinces occupied by Moscows troops.
Putin said the regions of Luhansk, Donetsk, Zaporizhzhya and Kherson are now part of Russia, during a televised ceremony in the Kremlin.
Russian occupation authorities staged referendums in the four areas in the past week which they said showed an overwhelming majority in favour of leaving Ukraine and joining Russia.
Ukraine and Western powers have dismissed the vote, saying the results were a foregone conclusion that would never be recognized internationally.
