So my understanding is that ultimately USA wants complete removal of Russian forces in Ukraine and the return of all the annexed regions to Ukraine. Obviously Russia doesn’t want to do this, but Russia knows that the the Donbas region is ethnically and culturally in support of Russianism, so the removal of Russian control of the region will likely bring further protesting and violence as pro-Russian separatism has been an issue since the Euromaiden.
Neither side will budge, because the ball is obviously in Russia’s hands until pro-Russian sentiment is weakened in the region. USA will never compromise to split the territory of Ukraine between Ukraine and Russia despite the fact this would be the quickest route to a resolution to the groundwar.
In other words this conflict could have been avoided if the pro-Russian regions were allowed to succeed following the Euromaiden, as they were strongly in support of he previous President and his pro-Russia ties, while the west was deeply condemning Yanukovych and his governments closeness to Russia.