Russia is advancing around Kostyantynivka and in the Sumy region with small, fast-moving units as both sides try a new tactic of using motorcycles and civilian cars to quickly cross open terrain.

It is designed to make the West think a Kremlin victory is inevitable.

Seizing complete control of the region − nearly one-third of which remains under Ukrainian control − has been a primary goal for the Kremlin. The arrival of summer has made it easier for Russian forces to advance.