Russia has used two new types of drones in five attacks over the last two to three weeks, according to Chernyak. The drones are made from materials like foam plastic and plywood.
One type carries a camera and a Ukrainian mobile phone SIM card to send images back to the Russian military.
"They identify where our mobile groups are positioned and where the machine guns are that can destroy them," Chernyak said. "They're trying to get a picture of where all our air defenses are located."
The new Russian drones with cameras do not carry explosives "but closely resemble regular Shahed drones" and operate in groups, Chernyak added.
The second new type of drone contains no explosive charge or only a small one and is being used as a decoy, he said. Because it is virtually indistinguishable from a regular attack drone from the ground, it still needs to be shot down, revealing the location of Ukraine's air defense systems.
The new drones probably cost as little as $10,000 each despite their long range, making them far cheaper to produce than air defense missiles, Chernyak said. The drones can also fly at an altitude of 1,000 meters, putting them out of range of machine guns and automatic rifles, he added.