Four disputed referendums have ended in Russian-controlled parts of Ukraine – votes that Moscow could use as grounds to annex more territory.
The votes have been denounced as a sham by the Ukrainian government and its Western allies, who see them as a Kremlin stunt.
Votes were held in the breakaway eastern regions of Donetsk and Luhansk.
Polls in the Russian-occupied parts of the southern regions of Kherson and Zaporizhzhia were also held.
In the absence of international recognition, the process has not been independently monitored for electoral fraud.
Refugees scattered across Russia were also able to vote at dozens of polling stations, including in annexed Crimea. Early voting results there indicated huge majorities in favor of joining Russia.
Up to four million people were invited to vote in the war-torn regions, which make up around 15% of Ukraine’s territory.
There is speculation that Russian President Vladimir Putin may announce the annexation of the four regions in a speech to a joint session of the Russian parliament on Friday.
In March 2014, he announced that Ukraine’s Crimean peninsula had joined Russia just days after a similarly unrecognized referendum was held.
If Russia annexes the four regions, it could take the war to a new and more dangerous level, with Moscow describing any attempt by Ukraine to reclaim them as an attack on its sovereign territory.
The UK responded to the referendums with new sanctions targeting senior Russian officials involved in vote enforcement, while the US warned Moscow it would impose new economic sanctions if it annexes more territory.
Ukrainian Foreign Minister Dmytro Kuleba called on the EU to impose more sanctions on Russia in response to the votes, which he said would not change Ukraine’s military plans.
“It will not be enough to limit oneself to cosmetic economic measures,” he said.
“We need an extremely serious and effective response with specific things that will hit the Russian economy. The softer the reaction to the so-called referendums, the more Russia is motivated to step up and annex new territories.
Mr Putin has defended the referendums, saying they were designed to end Ukraine’s persecution of ethnic Russians and Russian speakers – a charge the Ukrainian government denies.
“Saving the people in all the territories where this referendum is being held is at the center of our concerns and at the center of the attention of our whole society and our country,” the Russian leader said in televised remarks.