KYIV, Ukraine (AP) — 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 continue to hammer sites deep inside the country, Ukrainian President Volodymyr Zelenskyy says.

Ukraine has in recent months 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 invasion of its neighbor after more than four years of fighting and rattling Russian officials.