18 U.S.C. § 3244

When a treaty is in effect between the United States and a foreign country providing for the transfer of convicted offenders— (1) the country in which the offender was convicted shall have exclusive jurisdiction and competence over proceedings seeking to challenge, modify, or set aside convictions or sentences handed down by a court of such country; (2) all proceedings instituted by or on behalf of an offender transferred from the United States to a foreign country seeking to challenge, modify, or set aside the conviction or sentence upon which the transfer was based shall be brought in the court which would have jurisdiction and competence if the offender had not been transferred; (3) all proceedings instituted by or on behalf of an offender transferred to the United States pertaining to the manner of execution in the United States of the sentence imposed by a foreign court shall be brought in the United States district court for the district in which the offender is confined or in which supervision is exercised and shall name the Attorney General and the official having immediate custody or exercising immediate supervision of the offender as respondents. The Attorney General shall defend against such proceedings; (4) all proceedings instituted by or on behalf of an offender seeking to challenge the validity or legality of the offender’s transfer from the United States shall be brought in the United States district court of the district in which the proceedings to determine the validity of the offender’s consent were held and shall name the Attorney General as respondent; and (5) all proceedings instituted by or on behalf of an offender seeking to challenge the validity or legality of the offender’s transfer to the United States shall be brought in the United States district court of the district in which the offender is confined or of the district in which supervision is exercised and shall name the Attorney General and the official having immediate custody or exercising immediate supervision of the offender as respondents. The Attorney General shall defend against such proceedings.