Russian President Vladimir Putin on Wednesday announced a partial mobilization in Russia as the war in Ukraine reaches nearly seven months.

Putin’s address to the nation comes a day after Russian-controlled regions in eastern and southern Ukraine announced plans to hold votes on becoming integral parts of Russia. The Kremlin-backed efforts to swallow up four regions could set the stage for Moscow to escalate the war following Ukrainian successes on the battlefield.

The referendums, which have been expected to take since the first months of the war, will start Friday in the Luhansk, Kherson and partly Russian-controlled Zaporizhzhia and Donetsk regions.