As the leader of Vatican City, he is the head of a sovereign nation. But maintaining dual citizenship as a foreign head of state can “raise complex questions of international law,” according to the State Department.

A papal conclave is set to begin in Vatican City starting May 7, during which cardinals from around the world will elect the next leader of the Roman Catholic church. The tradition occurs any time a pope dies or resigns from the office. Pope Francis died April 21, the day after Easter.

All eyes are on Vatican City Tuesday with just over a day to go until the start of the papal conclave to elect the 267th pope.