Pub. L. 83-665, tit. V, ch. 2, sec. 528
Detail of Personnel to Foreign Governments.—
Sec. 528. Detail of Personnel to Foreign Governments.— (a) Whenever the President determines it to be consistent with and in furtherance of the purposes of this Act, the head of any United States Government agency is authorized to detail or assign any officer or employee of his agency to any office or position to which no compensation is attached with any foreign government or foreign government agency: Provided, That such acceptance of office shall in no case involve the taking of an oath of allegiance to another government. (b) Any such officer or employee, while so assigned or detailed, shall be considered, for the purpose of preserving his privileges, rights, seniority, or other benefits as such, an officer or employee of the Government of the United States and of the Government agency from which assigned or detailed, and he shall continue to receive compensation, allowances, and benefits from funds available to that agency or made available to that agency out of funds authorized under this Act.