US Code Title 17, Section 411 Registration and infringement actions
(a) Except for actions for infringement of copyright in Berne Convention works whose country of origin is not the United States and an action brought for a violation of the rights of the author under section 106A(a), and subject to the provisions of subsection (b) no action for infringement of the copyright in any work shall be instituted until registration of the copyright claim has been made in accordance with this title. In any case, however, where the deposit, application, and fee required for registration have been delivered to the Copyright Office in proper form and registration has been refused, the applicant is entitled to institute an action for infringement if notice thereof, together with a copy of the complaint, is served on the Register of Copyrights. . .