New Delhi, June 26 -- Russia is moving a significant part of its air defenses to protect a handful of prime targets, including Moscow, as Ukraine's long-range drones hammered sites deep inside the country, Ukrainian President Volodymyr Zelenskyy said.

In new overnight strikes, Zelenskyy said Thursday that Kyiv's forces hit two more Russian oil refineries in Ufa, 1,500 kilometers (930 miles) from the front line, and an oil depot in the Krasnodar region, 300 kilometers (180 miles) from Ukraine.

In recent months, Ukraine has stepped up its aerial campaign against Russian military installations and energy facilities. Its success has caused fuel shortages and disrupted army supply lines, stalling Moscow's full-scale invasion after more than ...