The Secretary, with the concurrence of the State, may detail Federal employees to State unemployment compensation administration and the Secretary may concur in the detailing of State employees to the United States Department of Labor for temporary periods for training or for purposes of unemployment compensation administration, and the provisions of section
869b of title
20 or any more general program of interchange enacted by a law amending, supplementing, or replacing section
869b of title
20 shall apply to any such assignment.