KYIV, Ukraine (AP) — Kremlin-orchestrated referendums that are expected to serve as a pretext for Moscow to annex Russian-held regions of Ukraine concluded Tuesday as the preordained outcome of the votes heightened tension between Russia and the West.

Moscow-backed officials in the four occupied regions in southern and eastern Ukraine said polls closed Tuesday afternoon after five days of voting and the counting of ballots had started.

The annexation of the regions which could happen as soon as Friday, sets the stage for a dangerous new phase in the seven-month war in Ukraine. Russia warned it could resort to deploying nuclear weapons to defend its own territory, including newly acquired lands.

After the five days of balloting, “the situation will radically change from the legal viewpoint, from the point of view of international law, with all the corresponding consequences for protection of those areas and ensuring their security,” Kremlin spokesman Dmitry Peskov said Tuesday.

Russian President Vladimir Putin has talked up Moscow’s nuclear option since last week following a Ukrainian counteroffensive that led to recent battlefield setbacks and has the Kremlin’s forces increasingly cornered.

The balloting that started Friday in the Kherson, Zaporizhzhia, Luhansk and Donetsk regions and a call-up of Russian military reservists ordered by Putin are other strategies aimed at buttressing Moscow’s exposed position.

Dmitry Medvedev, the deputy head of the Russian Security Council chaired by Putin, spelled out the threat in the bluntest terms yet Tuesday.

“Let’s imagine that Russia is forced to use the most powerful weapon against the Ukrainian regime that has committed a large-scale act of aggression, which is dangerous for the very existence of our state,” Medvedev wrote on his messaging app channel. “I believe that NATO will steer clear from direct meddling in the conflict in that case.”

The United States has dismissed the Kremlin’s nuclear talk as scare tactics.

Jake Sullivan, the US national security adviser, responded to Putin’s nuclear threats from last week. Sullivan told NBC on Sunday that Russia would pay a high, if unspecified, price if Moscow made good on threats to use nuclear weapons in the war in Ukraine.

The referendums ask residents whether they want the areas to become part of Russia. But the voting has been anything but free or fair.

Tens of thousands of residents had already fled the regions amid the war, and images shared by those who remained showed armed Russian troops going door-to-door to pressure Ukrainians into voting.

Mariupol Mayor Vadym Boychenko, who left the port city after the Russians finally seized it following a months-long siege, said only about 20 percent of the 100,000 estimated remaining residents cast ballots in the Donetsk referendum. Mariupol had a pre-war population of 541,000.

“A man toting an assault rifle comes to your home and asks you to vote, so what can people do?” Boychenko said during a news conference, explaining how people were coerced into voting.

Western allies sided firmly with Ukraine, dismissing the referendum votes as a sham.

French Foreign Minister Catherine Colonna said while visiting Kyiv on Tuesday that France was determined “to support Ukraine and its sovereignty and territorial integrity.”

She described the ballots as “mock referendums.” Ukrainian officials said Paris and Kyiv had moved closer to an agreement that would Ukrainian forces with French Caesar artillery systems.

Meanwhile, the mass call-up of Russians to active military duty has to some degree backfired on Putin.

It has triggered a massive exodus of men from the country, fueled protests in many regions across Russia and sparked occasional acts of violence. On Monday, a gunman opened fire in an enlistment office in a Siberian city and gravely wounded the local chief military recruitment officer. The shooting came after scattered arson attacks on enlistment offices.

With Putin’s back against the wall amid Ukraine’s recent battlefield successes, Russian media speculated he might follow up on last week’s partial mobilization order by declaring martial law and shutting the nation’s borders for all men of fighting age.

Russian officials announced plans to set up a military recruitment office right on the border with Georgia, one of the main routes of the exodus.

As Moscow works to build up its troops in Ukraine, Russian shelling continued to claim lives. At least 11 civilians were killed and 18 others wounded by Russian barrages in 24 hours, Ukraine’s presidential office said Tuesday.

Among the casualties were eight people, including a 15-year-old boy, who were killed by a Russian strike on the town of Pervomaiskyi in the northeastern Kharkiv region.

Pavlo Kyrylenko, governor of the eastern Donetsk region where shells killed three people, said that “every day of the referendum we count more dead in the Donbas, and those sad numbers show Russia’s real goals.”

Donetsk and Luhansk, which Moscow-backed separatists have partly controlled for eight years, together make up Ukraine’s industrial Donbas region.

A monitoring mission set up by the UN human rights office on Tuesday issued its first comprehensive look at rights violations and abuses committed by Russia and Ukraine between February 1 and July 31, a period that covers the first five months of Russia’s invasion.

Matilda Bogner, the mission’s chief, said Ukrainian prisoners of war appeared to have faced “systematic” mistreatment, “not only upon their capture, but also following their transfer to places of internment” in Russian-controlled areas of Ukraine and Russia itself.

The Ukraine war is still gripping world attention, as it causes widespread shortages and rising prices not only for food but for energy, inflation hitting the cost of living everywhere, and growing global inequality. The talk of nuclear war has only deepened the concern.

Misery and hardship are often the legacy of Russia’s occupation of Ukrainian areas now recaptured by Kyiv’s forces. Some people have had no gas, electricity, running water or internet since March.

The war has brought an energy crunch for much of Western Europe, with German officials seeing the disruption of Russian supplies as a power play by the Kremlin to pressure Europe over its support for Ukraine.

The German economy ministry said Tuesday that the Nord Stream one (1) pipeline leading from Russia to Europe has reported a drop in pressure, only hours after a leak was reported in the Nord Stream two (2) pipeline in the Baltic Sea off Denmark. Both pipelines were built to carry natural gas from Russia to Europe.

The extent of the damage means that the pipelines are unlikely to be able to carry any gas to Europe this winter even if there was the political will to bring them online, analysts at the Eurasia Group said.

Peskov, the Kremlin spokesman, said the problems were “very alarming” and would be investigated.

Meta, which owns Facebook and Instagram, revealed another prong of Russia’s offensive: a sprawling disinformation network.

The network originating in Russia aimed to use hundreds of fake social media accounts and dozens of sham news websites to spread biased Kremlin talking points about the invasion of Ukraine, Meta said Tuesday.