 He received his episcopal consecration on the following 10 December from Cardinal Domenico Serafini, OSB, with Bishops Joseph Legrand, CSC, and Agostino Zampini, OSA, serving as co-consecrators, in the chapel of the Urbaniana University.In this post, he actively tried to improve relations between the Vatican and the Emperor of Japan.Biondi was later named Apostolic Delegate to Japan on 6 December 1919, Secretary of the Congregation for the Propagation of the Faith on 14 June 1921 and Apostolic Delegate to the United States on 14 December 1922.