President Vladimir Putin ordered a partial military mobilization and vowed on Wednesday to use “all available means” to protect Russian territory after Moscow-controlled regions of Ukraine suddenly announced referendums on annexation.

The votes, already denounced as “sham” by Kyiv and the West, will dramatically up the ante in Ukraine’s seven-month-old conflict by allowing Moscow to accuse Ukrainian forces of attacking its own territory.

Four Russian-held regions of Ukraine — Donetsk and Lugansk in the east, and Kherson and Zaporizhia in the south — said Tuesday they would hold the polls over five days from Friday.

In a pre-taped address to the nation early Wednesday, Putin accused the West of wanting to “destroy” his country by supporting Kyiv and said Russia must support those in Ukraine who wanted to “determine their own future”.

The Russian leader announced a partial military mobilization, with Defense Minister Sergei Shoigu telling state television that around 300,000 reservists would be called up.

“If the territorial integrity of our country is threatened, we will certainly use all means at our disposal to protect Russia and our people. This is not a bluff,” Putin said.

“Those who are trying to blackmail us with nuclear weapons should know that the tide can also turn in their direction,” Putin added.

Putin said that by supporting Ukraine, the West is trying to “weaken, divide and ultimately destroy our country,” while Shoigu said Moscow is fighting in Ukraine “not so much against Ukraine as against the collective West “.

Moscow’s sudden spate of movements this week came as Russian forces in Ukraine faced their biggest challenge since the conflict began.

In a rare admission of military casualties from Moscow, Shoigu said Wednesday that 5,937 Russian soldiers have died in Ukraine since the military intervention began in February.

In a full-scale Ukrainian counteroffensive in recent weeks, Kiev forces have retaken hundreds of towns and villages that have been under Russia’s control for months.

The referendums follow a pattern first established in 2014 when Russia annexed the Crimean Peninsula from Ukraine after a similar vote.

As in 2014, Washington, Berlin and Paris condemned the recent referendums and said the international community will never recognize the results.

Chancellor Olaf Scholz said they were a “sham,” French President Emmanuel Macron called them a “travesty,” and White House national security adviser Jake Sullivan said they were “an affront to the principles of sovereignty and territorial integrity.” “.

“Mock referendums and mobilization are signs of weakness, of Russian failure,” US Ambassador to Ukraine Bridget Brink said on Twitter.

“I thank all friends and partners of Ukraine for their massive and unequivocal condemnation of Russia’s intentions to organize more pseudo-referendums,” said Ukrainian President Volodymyr Zelenskyy.

Kyiv said the referendums were meaningless and vowed to “eliminate” threats posed by Russia, saying its forces would continue to retake territory regardless of what Moscow or its proxies announced.

Political scientist Tatyana Stanovaya said the announcements were a direct result of the success of Ukraine’s eastern counteroffensive.

“Putin does not want to win this war on the battlefield. Putin wants to force Kyiv to surrender without a fight,” she said.

Meanwhile, the Ukrainian nuclear operator Energoatom accused Russia on Wednesday of attacking the Zaporizhia nuclear power plant in southern Ukraine again.

The strike damaged a power line, shutting down several transformers at the plant’s number six reactor and forcing a brief start-up of emergency generators, Energoatom said.

“Even the presence of inspectors from the International Atomic Energy Agency (IAEA) does not stop the Russians,” it said, calling on the agency to “take more decisive action” against Moscow.

Europe’s largest nuclear facility, located on Russian territory, has become a focus of concern after claims of attacks there were rebelled.