22 U.S.C. § 279a

There is hereby authorized to be appropriated, out of any money in the Treasury not otherwise appropriated, such sums as may be required for expenditure under the direction of the Secretary of State, for the payment by the United States of its proportionate share in the expenses of the Organization: Provided , That the percentage contribution of the United States to the total annual budget of the Organization shall not exceed 33.33 per centum.