Russia is beefing up its forces for a new assault on Ukraine¡¯s eastern Donbas region, setting the stage for a protracted battle that is certain to inflict heavy losses on both sides as the Russians try to encircle Ukraine¡¯s fighters, analysts said.

Military analysts are wary of predicting who will win the battle for Ukraine¡®s industrial heartland of Donbas, a crucial conflict that will likely be brutal and ultimately define the course of the war.

¡°The outcome of the battle could be that both sides will be battered to the point when neither one will be able to conduct an offensive or a counteroffensive,¡± said Konrad Muzyka, director of the Poland-based Rochan consultancy.