Ukrainian forces are continuing to make gains in a key eastern region. Officials say the counteroffensive has pushed the Russians out of two cities in Kharkiv. A US think tank says most of the region is now under Ukrainian control.

The Institute for the Study of War says Russian forces are fleeing Kharkiv to avoid being surrounded in the city of Izyum. It's a strategic point for Russia's supply routes to the frontline.

The Russians have been trying to take control of the entire Donetsk region. The think tank says the city's liberation would stop their advance from the northwest.

Intelligence from the United Kingdom also says Ukrainian artillery attacks may have prevented Russia from bringing reserves across a river in the southern region of Kherson. It says the majority of Russian forces in Ukraine are now likely focused on defensive actions.