The head of the apostolic nunciature is called a nuncio, an ecclesiastical diplomatic title. A papal nuncio (officially known as an apostolic nuncio) is a permanent diplomatic representative (head of diplomatic mission) of the Holy See to a state or to one of two international intergovernmental organizations, the European Union or ASEAN, having the rank of an ambassador extraordinary and plenipotentiary, and the ecclesiastical rank of titulararchbishop. Papal representatives to other intergovernmental organizations are known as "permanent observers" or "delegates".
In several countries that have diplomatic relations with the Holy See, the apostolic nuncio is ipso facto the dean of the diplomatic corps. The nuncio is, in such a country, first in the order of precedence among all the diplomats accredited to the country, and he speaks for the diplomatic corps in matters of diplomatic privilege and protocol. Most countries that concede priority to the nuncio are officially Catholic, but some are not.
In addition, the nuncio serves as the liaison between the Holy See and the Church in that particular nation. The nuncio has an important role in the selection of bishops.
Pacific Ocean: Countries of the Pacific Ocean are currently represented overall by the nuncio to New Zealand, who serves as the apostolic delegate in the Pacific Ocean.[3][4]
Of entities that have established diplomatic relations with the Holy See, there is no representative accredited to the Order of Malta (which is also headquartered in Rome).[5]
The Holy See does not have relations with fifteen countries:
An apostolic delegate may be sent to liaison between the Catholic Church and a country with which the Holy See has no diplomatic ties, though not accredited to the government of the country. Apostolic delegates have no formal diplomatic status, though in some countries they have some diplomatic privileges.
Africa:
Comoros, Mauritania, Somalia
Asia:
The Arabian Peninsula, Brunei, Laos, Myanmar, Vietnam
the Americas:
the Antilles (Anguilla, Antigua and Barbuda, Aruba, Bahamas, Barbados, Belize, Bermuda, British Virgin Islands, Cayman Islands, Dominica, French Guiana, Grenada, Guadeloupe, Guyana, Jamaica, Martinique, Montserrat, Netherlands Antilles, Saint Kitts and Nevis, Saint Lucia, Suriname, Trinidad and Tobago, Turks and Caicos Islands, Saint Vincent and Grenadines)