The fast-moving developments in Trump's near-back-to-back summits with the heads of Russia, Ukraine and European powers have highlighted a pair of repeated sticking points.

Ukraine's air force said Russia launched 72 drones and one Iskander-M ballistic missile into the country in its latest overnight barrage, of which 48 drones were intercepted or suppressed. The missile and 24 drones impacted across 10 locations, the air force said.