The president will be in Italy to attend the Group of Eight meeting from July 8 to 10, during part of an international tour that also includes Russia and Ghana.

According to the National Catholic Register, the White House explained that the notable absence is because details of the president's tour are still pending: "We won’t go into the details of who he’s meeting and the places he'll be visiting until nearer the time," a spokesman said.

The Register also reported that the Vatican is hoping for a presidential visit.

Father Ciro Benedettini, deputy director of the Vatican Press Office, said the Holy See is "waiting" to hear from the U.S. administration, but that as of last week no contact by the current administration had been made. Additionally, the president has yet to name a U.S. ambassador to the Holy See.

Heads of state visiting Italy traditionally also visit the Pontiff.