22 CFR §50.3

1. (a)A person abroad who claims U.S. nationality, or a representative on his behalf, may apply at a consular post for registration to establish his claim to U.S. nationality or to make his residence in the particular consular area a matter of record.
2. (b)The applicant shall execute the registration form prescribed by the Department and shall submit the supporting evidence required by subpart C of part 51 of this chapter. A diplomatic or consular officer or a designated nationality examiner shall determine the period of time for which the registration will be valid.