shall, unless exigent circumstances require otherwise, notify the Director in writing regarding any proposed change in policies relating to the activities of that agency under the National Drug Control Program prior to implementation of such change. The Director shall promptly review such proposed change and certify to the head of that agency in writing whether such change is consistent with the National Drug Control Strategy. (2) Exception If prior notice of a proposed change under paragraph (1) is not practicable— (A) the head of the National Drug Control Program Agency shall notify the Director of the proposed change as soon as practicable