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—