Archbishop Leanza, 68, had served as the nuncio to Ireland since 2008, and has recently been at the center of a diplomatic incident between the Vatican and the government of Ireland after the latter published the Cloyne report in July.
The 400-page report deemed the Vatican negligent in the safeguarding of children, and demanded answers to accusations that it had given some clergy the go-ahead to cover-up sexual abuse cases involving priests.
In particular, the report found that Bishop John Magee of Coyne, who resigned in 2010, ignored the 1996 child protection guidelines set down by the Irish Catholic Bishops' Conference and failed to report to the police at least nine of 15 sexual abuse allegations in that period.
Archbishop Leanza was called back to the Vatican for meetings, and was instrumental in crafting the official response, released Sept. 3, in which the Vatican firmly denied the accusations.
Archbishop Leanza was ordained in 1966, and in 1990 he was given his first assignment as a Vatican diplomat in Haiti. Since then, he has also served in Malawi, Zambia, Bosnia-Herzegovina, Slovenia, Macedonia and Bulgaria.