The nuncio serves both as the ambassador of the Holy See to the government of the United States and as delegate and point-of-contact between the Catholic hierarchy in America and the pope.

The physical building which houses the offices of the apostolic nuncio and his staff is called the Nunciature to the United States of America.

[a] At its establishment in 1893, the Apostolic Delegation occupied temporary quarters at the Catholic University of America, then from 1894 on a row of antebellum houses north of the United States Capitol.

It moved in 1907 into a new home at 1811 Biltmore Street NW, designed for that purpose in 1905 by architect Albert Olszewski Von Herbulis (razed in 1973).

[4] The current site of the Apostolic Nunciature on Massachusetts Avenue was acquired in 1931 for $223,000 and the construction of the building, a three-story complex that includes a chancery, other offices and residential quarters, was completed in 1937 at a cost of $550,000.