22 U.S.C. § 4011

Except as provided in section 4010(a)(2) of this title, the Secretary may terminate at any time the appointment of any member of the Service serving under a limited appointment who is in the Senior Foreign Service, who is assigned to a salary class in the Foreign Service Schedule or who is paid in accordance with section 3967 of this title or is a United States citizen paid under a compensation plan under section 3968 of this title.