If any person who is within the United States claims a right or privilege as a national of the United States and is denied such right or privilege by any department or independent agency, or official thereof, upon the ground that he is not a national of the United States, such person may institute an action under the provisions of section
2201 of title
28 against the head of such department or independent agency for a judgment declaring him to be a national of the United States, except that no such action may be instituted in any case if the issue of such person’s status as a national of the United States