Vladimir Putin has expanded Russia's nuclear arsenal for the fourth consecutive year while warning Nato that deploying troops to Ukraine would mean war with Russia. The increase, revealed by the Stockholm International Peace Research Institute, comes as tensions escalate over Western support for Kyiv, with Putin denying Russia poses any threat to Nato states even as his deputy security council chief raised the prospect of nuclear strikes on a Baltic member.

Russia's stockpile of deployed nuclear warheads on missiles and bombers rose by 78 over the past year to 1,796, the highest level in nine years, while the US made no increase and Britain and France held steady at 170 and 280 warheads respectively. Speaking at the BRICS summit in New Delhi, Putin cast any Western troop deployment to Ukraine as an act of war, while former president Dmitry Medvedev separately warned that Lithuania could be reduced to "scorched earth" if it hosted Nato nuclear weapons. The report coincided with fresh Russian strikes killing and wounding civilians in Odesa, Kryvyi Rih and Zaporizhzhia, Ukrainian drone attacks on Russian military and chemical facilities, and UK figures putting Russian war dead at roughly half a million with a million more wounded.