(a) In general
The President is authorized to implement and carry out the provisions of this chapter and the Additional Protocol and shall designate through Executive order which executive agency or agencies of the United States, which may include but are not limited to the Department of State, the Department of Defense, the Department of Justice, the Department of Commerce, the Department of Energy, and the Nuclear Regulatory Commission, shall issue or amend and enforce regulations in order to implement this chapter and the provisions of the Additional Protocol.

(b) Included authority
For any executive agency designated under subsection (a) that does not currently possess the authority to conduct site vulnerability assessments and related activities, the authority provided in subsection (a) includes such authority.

(c) Exception
The authority described in subsection (b) does not supersede or otherwise modify any existing authority of any Federal department or agency already having such authority.