Russia insists nuclear weapons could be used to defend occupied Ukraine territories

Russia has promised “full protection” up to the use of nuclear weapons for the regions of Ukraine that it plans to annex by the end of the month.

Asked whether Russia’s nuclear doctrine would apply to four Ukrainian regions that it is expected to absorb, Sergey Lavrov, the foreign minister, said that “all of Russia’s laws, doctrines and concepts” would apply. Russia’s nuclear doctrine allows their use if the country faces an “existential threat”.

Ukraine has reported that Russian forces had launched dozens of missile attacks and airstrikes on military and civilian targets in the past 24 hours.

In Russia more than 700 people were detained on Saturday as they braved prosecution or immediate drafting to the army to protest against President Putin’s mobilisation of 300,000 reservists. In his announcement last week, Putin said that Russia had “various weapons of destruction” to rival Nato’s, and that it would “use all means” if its territorial integrity was threatened. He added: “I’m not bluffing.”

Speculation has been rife that the Kremlin may use tactical nuclear weapons. Short-range tactical weapons have never been used in conflict but some experts fear that Moscow could use a limited strike as a “game changer” if it faces more setbacks after the recent Ukrainian counter-offensive.

Jake Sullivan, the US national security adviser, said that Russia would face “catastrophic consequences” and that the US would “respond decisively” if nuclear weapons were used in Ukraine.

On Saturday Putin fired Dmitry Bulgakov, the deputy defence minister in charge of logistics in Ukraine.

The Kremlin has made clear that any Ukrainian attempt to regain territory would be seen as a direct attack on Russia, abetted by the West. Lavrov said that it was “absolutely natural” that the territory would acquire the protections of the Russian Federation, which consists of 83 “federal subjects” plus annexed Crimea and Sevastopol.

President Zelensky of Ukraine said yesterday: “We will liberate our entire country, from Kherson to the Luhansk region, from Crimea to the Donetsk region . . . Every murderer and torturer will be brought to justice for what he did against Ukrainians.”

Referendums in which residents are asked if they want their regions to be incorporated by Russia continued yesterday in Kherson, Zaporizhzhia, Luhansk and Donetsk provinces. Russian media said an interim poll had indicated 93 per cent support in Kherson.

Putin approved new legislation at the weekend introducing long jail terms for desertion or “voluntary surrender”.

Formally, only men who have served in the army or studied at military institutes are due to be drafted in the “partial” mobilisation but social media and independent news outlets have been full of stories of the army seizing men with no military experience, or with other reasons to be exempt.

Female pro-Kremlin bloggers in Russia’s far east have been writing posts in which they compare the drafting of 300,000 men out of a possible total of 25 million reservists to taking one candied jelly from a whole packet of sweets.

A source close to Putin’s administration told the Meduza website that Russia was planning to restrict exit from the country for men of draft age on Wednesday, a day after the referendum votes close.

Estonia warned residents with Russian citizenship that they could be banned from the EU if they went to Russia to join up.