Trump's comments mark his latest criticism of Putin for his reluctance to agree to a U.S.-proposed ceasefire and for Moscow's continuing bombardment of Ukraine.

Ukraine has been hit by the biggest ever aerial attack from Russia - 728 drones and 13 cruise or ballistic missiles hit cities around the country in multiple waves.

The sound of low-flying drones and explosions from air defense systems could be heard for hours in sections of the capital, as residents fled to the safety of subway stations, underground car garages ...