(Reuters) - Russia is facing its most difficult situation in three decades due to unprecedented Western sanctions, but foreign attempts to isolate it from the global economy will fail, Prime Minister Mikhail Mishustin said on Thursday.

       He also said the situation provided room for new business opportunities as foreign companies leaving Russia would make space for others.

       Western countries are progressively tightening a barrage of economic sanctions imposed to try to force Russia to end its military operation in Ukraine and withdraw its forces.

       (The story is refiled to corrects Russian to Russia in headline)

       (Reporting by Reuters; Editing by Kevin Liffey)