(a) Whenever the President notifies the Attorney General that he has denied a request for clemency, the Attorney General shall so advise the petitioner and close the case.

(b) Except in cases in which a sentence of death has been imposed, whenever the Attorney General recommends that the President deny a request for clemency and the President does not disapprove or take other action with respect to that adverse recommendation within 30 days after the date of its submission to him, it shall be presumed that the President concurs in that adverse recommendation of the Attorney General, and the Attorney General shall so advise the petitioner and close the case.