Reconcile God's sovereignty with Satan being the god of this world

In Matthew 4:8-9 we read about the temptation of Christ by Satan: > Again, the devil took Him up on an exceedingly high mountain, and > showed Him all the kingdoms of the world and their glory. And he said > to Him, “All these things I will give You if You will fall down and > worship me.” In Christ's response, he did not challenge Satan's authority to make such a claim. Taken together with 2 Cor 4:4 where Satan is described as "the god of this world" it seems we can conclude that Satan is the ruler of the world. How can we reconcile this with God's sovereignty?