In furtherance of the purposes of this chapter, the head of any agency of the United States Government is authorized to detail, assign, or otherwise make available any officer or employee of his agency (1) to serve with, or as a member of, the international staff of any international organization, or (2) to any office or position to which no compensation is attached with any foreign government or agency thereof: Provided, That such acceptance of such office or position shall in no case involve the taking of an oath of allegiance to another government.
Any such officer or employee, while so detailed or assigned, shall be considered, for the purpose of preserving his allowances, privileges, rights, seniority, and other benefits as such, an officer or employee of the United States Government and of the agency of the United States Government from which detailed or assigned, and he shall continue to receive compensation, allowances, and benefits from funds authorized by this chapter. He may also receive, under such regulations as the President may prescribe, representation allowances similar to those allowed under section 4085 of this title. The authorization of such allowances and other benefits, and the payment thereof out of any appropriations available therefor, shall be considered as meeting all of the requirements of section 5536 of title 5.