Russian forces are bypassing a key stronghold in eastern Ukraine that they have fought for months to capture and are focusing instead on cutting supply lines to it, a Ukrainian official said Monday.

Russian troops are going around the vital logistics hub of Pokrovsk, where a steadfast Ukrainian defense has kept them at bay, and are taking aim at a highway that leads from there to the central Ukraine city of Dnipro, Maj. Viktor Trehubov, a local Ukrainian army spokesperson, told The Associated Press.