Were Sauron's power closer to a Valar than a Maiar?

He made the one ring so indestructible that even Maiar like Gandalf and Saruman do not have the will power to resist it. Nor can they destroy it. He made a entire region into his domain(Mordor). He used magic to convert Kings of Men into Nazguls. He can control the weather by brining dark clouds to cover his orcs and trolls. So was his power almost the same as a Valar?