Ukraine president Volodymyr Zelenskyy has vowed to regain territory lost to Russia - after forces withdrew from Lysychansk in the east.
It's the last main city to fall in Luhansk, an area making up part of the Donbas which Moscow wants to fully control.
The region's governor says it's neither a "critical" setback or a sign of defeat in the war.
Defence expert Professor Michael Clarke says while Luhansk's fallen, Russia's not achieved its aims.
"The bigger one is Donetsk.
"Russian forces occupy about half of Donestsk, they occupy the eastern half but not the western half.
"They won't get the whole of Donestk until they take Slovyansk and Kramatorsk, which will be quite a struggle for them."
