The Secretary may provide to personnel appointed or assigned by the Secretary to serve abroad, allowances and benefits similar to those provided under chapter 9 of title I of the Foreign Service Act of 1980 (
22 U.S.C.
4081 et seq.). Leaves of absence for personnel under this subsection shall be on the same basis as that provided under subchapter
I of chapter
63 of title
5 or section 903 of the Foreign Service Act of 1980 (
22 U.S.C.
4083) to individuals serving in the Foreign Service.