Where the subject matter of an action or proceeding pending in a State court relates to an arbitration agreement or award falling under the Convention, the defendant or the defendants may, at any time before the trial thereof, remove such action or proceeding to the district court of the United States for the district and division embracing the place where the action or proceeding is pending. The procedure for removal of causes otherwise provided by law shall apply, except that the ground for removal provided in this section need not appear on the face of the complaint but may be shown in the petition for removal. For the purposes of Chapter 1 of this title any action or proceeding removed under this section shall be deemed to have been brought in the district court to which it is removed.