In a word: no.
In two words: hell no.
Martin is a novelist, Tolkien was not. Tolkien was a linguist and creator. The stories that we have are derivative of his lifetime of work and serious scholarship that recreated the entire field of “fairy tales”, as Tolkien described his own work.
Martin’s work, while very good, is derivative of Tolkien’s establishment of the modern Sword and Sorcery genre.
Martin is not the “American Tolkien” any more than Terry Brooks or Robert Jordan were. He is the hottest thing in the genre right now, but he doesn’t compare to man who created an entire genre of literature.
All without being a novelist.
All of this.
Thank you.