The United States shall be represented on the Commission by three United States Commissioners to be appointed by the President and to serve at his pleasure. The Commissioners shall receive no compensation for their services as Commissioners. Each United States Commissioner shall be appointed for a term of office not to exceed 2 years, but is eligible for reappointment. Any United States Commissioner may be appointed for a term of less than 2 years if such appointment is necessary to ensure that the terms of office of not more than two Commissioners will expire in any 1 year. A vacancy among the United States Commissioners shall be filled by the President in the manner in which the original appointment was made, but any Commissioner appointed to fill a vacancy occurring before the expiration of the term for which the Commissioner's predecessor was appointed shall be appointed only for the remainder of such term. Of the Commissioners-
The Secretary of State, in consultation with the Secretary, may designate from time to time alternate United States Commissioners to the commission. An Alternate United States Commissioner may exercise, at any meeting of the Commission, all powers and duties of a United States Commissioner in the absence of a duly designated Commissioner for whatever reason. The number of such alternate United States Commissioners that may be designated for any such meeting shall be limited to the number of authorized United States Commissioners that will not be present.
16 U.S.C. § 773a