In carrying out transactions authorized by section 521 of this title, the Secretary of the Army and the Secretary of the Navy are authorized, in their discretion and provided that it be not inconsistent with any defense requirements of the United States or of its possessions, to communicate or transmit to the government of any American republic or to any duly authorized person for the use of such government information pertaining to the arms, ammunition, or implements of war sold under the terms of that section or to any vessels of war constructed within the jurisdiction of any such government, and to export for the use of any such government coast defense and antiaircraft matériel and ammunition therefor, and vessels of war and their armament and equipment involving such information: Provided, That any information thus communicated or transmitted or involved in any such arms, ammunition, implements of war, or equipment when exported shall cease to be considered restricted after one year from the date that such communication or transmission has been authorized or such exportation made.