The U.S. ambassador to the Vatican Miguel H. Diaz is resigning his post to become a professor at a university.
The U.S. Embassy said Wednesday that Diaz, a Hispanic Roman Catholic theologian, will join his family in Ohio where he has been named a professor of faith and culture at the University of Dayton.
The Cuban-born Diaz was an adviser to President Barack Obama's 2008 presidential campaign. His term as ambassador has been marked by tension between Washington and the Vatican over Obama's support of abortion in contrast with core church teaching.
Diaz had a farewell audience with Pope Benedict XVI earlier this week.