8 U.S.C. § 1421 : US Code - Section 1421: Naturalization authority

    (a) Authority in Attorney General
      The sole authority to naturalize persons as citizens of the
    United States is conferred upon the Attorney General.
    (b) Court authority to administer oaths
      (1) Jurisdiction
        Subject to section 1448(c) of this title - 
        (A) General jurisdiction
          Except as provided in subparagraph (B), each applicant for
        naturalization may choose to have the oath of allegiance under
        section 1448(a) of this title administered by the Attorney
        General or by an eligible court described in paragraph (5).
        Each such eligible court shall have authority to administer
        such oath of allegiance to persons residing within the
        jurisdiction of the court.
        (B) Exclusive authority
          An eligible court described in paragraph (5) that wishes to
        have exclusive authority to administer the oath of allegiance
        under section 1448(a) of this title to persons residing within
        the jurisdiction of the court during the period described in
        paragraph (3)(A)(i) shall notify the Attorney General of such
        wish and, subject to this subsection, shall have such exclusive
        authority with respect to such persons during such period.
      (2) Information
        (A) General information
          In the case of a court exercising authority under paragraph
        (1), in accordance with procedures established by the Attorney
        General - 
            (i) the applicant for naturalization shall notify the
          Attorney General of the intent to be naturalized before the
          court, and
            (ii) the Attorney General - 
              (I) shall forward to the court (not later than 10 days
            after the date of approval of an application for
            naturalization in the case of a court which has provided
            notice under paragraph (1)(B)) such information as may be
            necessary to administer the oath of allegiance under
            section 1448(a) of this title, and
              (II) shall promptly forward to the court a certificate of
            naturalization (prepared by the Attorney General).
        (B) Assignment of individuals in the case of exclusive
          authority
          If an eligible court has provided notice under paragraph
        (1)(B), the Attorney General shall inform each person (residing
        within the jurisdiction of the court), at the time of the
        approval of the person's application for naturalization, of - 
            (i) the court's exclusive authority to administer the oath
          of allegiance under section 1448(a) of this title to such a
          person during the period specified in paragraph (3)(A)(i),
          and
            (ii) the date or dates (if any) under paragraph (3)(B) on
          which the court has scheduled oath administration ceremonies.

        If more than one eligible court in an area has provided notice
        under paragraph (1)(B), the Attorney General shall permit the
        person, at the time of the approval, to choose the court to
        which the information will be forwarded for administration of
        the oath of allegiance under this section.
      (3) Scope of exclusive authority
        (A) Limited period and advance notice required
          The exclusive authority of a court to administer the oath of
        allegiance under paragraph (1)(B) shall apply with respect to a
        person - 
            (i) only during the 45-day period beginning on the date on
          which the Attorney General certifies to the court that an
          applicant is eligible for naturalization, and
            (ii) only if the court has notified the Attorney General,
          prior to the date of certification of eligibility, of the day
          or days (during such 45-day period) on which the court has
          scheduled oath administration ceremonies.
        (B) Authority of Attorney General
          Subject to subparagraph (C), the Attorney General shall not
        administer the oath of allegiance to a person under subsection
        (a) of this section during the period in which exclusive
        authority to administer the oath of allegiance may be exercised
        by an eligible court under this subsection with respect to that
        person.
        (C) Waiver of exclusive authority
          Notwithstanding the previous provisions of this paragraph, a
        court may waive exclusive authority to administer the oath of
        allegiance under section 1448(a) of this title to a person
        under this subsection if the Attorney General has not provided
        the court with the certification described in subparagraph
        (A)(i) within a reasonable time before the date scheduled by
        the court for oath administration ceremonies. Upon notification
        of a court's waiver of jurisdiction, the Attorney General shall
        promptly notify the applicant.
      (4) Issuance of certificates
        The Attorney General shall provide for the issuance of
      certificates of naturalization at the time of administration of
      the oath of allegiance.
      (5) Eligible courts
        For purposes of this section, the term "eligible court" means -
      
          (A) a district court of the United States in any State, or
          (B) any court of record in any State having a seal, a clerk,
        and jurisdiction in actions in law or equity, or law and
        equity, in which the amount in controversy is unlimited.
    (c) Judicial review
      A person whose application for naturalization under this
    subchapter is denied, after a hearing before an immigration officer
    under section 1447(a) of this title, may seek review of such denial
    before the United States district court for the district in which
    such person resides in accordance with chapter 7 of title 5. Such
    review shall be de novo, and the court shall make its own findings
    of fact and conclusions of law and shall, at the request of the
    petitioner, conduct a hearing de novo on the application.
    (d) Sole procedure
      A person may only be naturalized as a citizen of the United
    States in the manner and under the conditions prescribed in this
    subchapter and not otherwise.