Article 8 Vienna Convention on Diplomatic Relations
1.Members of the diplomatic staff of the mission should in principle be of the nationality of the sending State.
2.Members of the diplomatic staff of the mission may not be appointed from among persons having the nationality of the receiving State, except with the consent of that State which may be withdrawn at any time.
3.The receiving State may reserve the same right with regard to nationals of a third State who are not also nationals of the sending State.
See also: Article 7 Vienna Convention on Diplomatic Relations
