Kyiv, Ukraine-Moscow-held regions of Ukraine begin voting Friday on whether to become part of Russia, in referendums that Kyiv and its allies have condemned.

The referendums in eastern Donetsk and Lugansk regions, as well as in the southern Kherson and Zaporizhzhia regions have come after Putin announced this week a mandatory troop call-up for about 300,000 reservists.

The mobilisation comes after Ukrainian forces seized back most of the northeastern Kharkiv region in a huge counter-offensive that has seen Kyiv retaking hundreds of towns and villages under Russian control for months.

The four regions’ integration into Russia -- which for most observers is already a foregone conclusion would represent a major new escalation of the conflict.

“We cannot we will not -- allow President Putin to get away with it,” US Secretary of State Antony Blinken said in a UN Security Council session on Thursday, lashing out against the referendums as a “sham”. “The very international order we’ve gathered here to uphold is being shredded before our eyes. (Defending Ukraine’s sovereignty) is about protecting an international order where no nation can redraw the borders of another by force,” he said. 

The referendums are reminiscent of a similar sort in 2014 that saw the Crimean Peninsula in Ukraine annexed by Russia. Western capitals have maintained that the vote was fraudulent and hit Moscow with sanctions in response.