Kyiv observed a day of mourning Friday after a Russian missile and drone barrage killed 31 people, including five children, and injured more than 150 in the Ukrainian capital. Officials said it was the deadliest attack on the city since July last year and the highest single-day toll of child casualties since Russian aerial strikes on Kyiv began in October 2022. The youngest victim was 2 years old. Ukrainian President Volodymyr Zelenskyy said 16 children were among the wounded. The assault destroyed part of a nine-story residential building and damaged more than 100 other structures, including schools, medical facilities, and universities. Emergency crews continued digging through rubble overnight as the death toll climbed. Authorities said Russia's escalating campaign of strikes on urban centers ignores Western calls, including from U.S. President Donald Trump, to stop targeting civilians after more than three years of war. Zelenskyy said Russia fired more than 5,100 glide bombs, 3,800 Shahed drones, and nearly 260 missiles — 128 of them ballistic — in July alone. He urged stronger economic sanctions on Moscow, arguing they work despite Kremlin denials. His comments followed Trump's remark Thursday that he wasn't sure sanctions "bother" Russian President Vladimir Putin. Putin on Friday reaffirmed that Moscow's ceasefire conditions remain unchanged and said recent prisoner-exchange talks in Istanbul were "valuable" despite no broader progress. He also announced production had begun on Russia's newest hypersonic missile, the Oreshnik, capable of carrying multiple warheads at speeds up to Mach 10. Ukraine has called for an urgent U.N. Security Council meeting to press for "a full, immediate and unconditional ceasefire." On the battlefield, Ukrainian forces are under pressure in the strategic eastern city of Chasiv Yar in Donetsk, where Russia is pushing to break through after 18 months of fighting. Zelenskyy rejected Russian claims the city had fallen, though the Institute for the Study of War said Ukraine's hold is weakening and warned the loss could open multiple routes for Russian advances into Ukraine's defensive fortress belt. Russia's Defense Ministry said its forces shot down 60 Ukrainian drones overnight, more than half over the Belgorod region bordering Ukraine. Ukraine's air force reported downing 44 of 72 Russian drones launched overnight. — Agencies