Following similar gatherings in 2013 and 2016, the Vatican press office said the convocation is a way for Pope Francis to "consolidate" the practice of the Vatican diplomats meeting every three years.

Since the previous meeting, Pope Francis added a third section -- the Section for Diplomatic Personnel -- to the Vatican Secretariat of State; the section, established in 2017, prepared the June meeting.

The Vatican press office said June 10 that 103 diplomats were expected to take part -- 98 nuncios and five permanent observers. In addition, 46 retired nuncios were invited to join the others June 15, the day Pope Francis will celebrate Mass with the nuncios and host a luncheon for them.

Pope Francis was scheduled to address the diplomats June 13. Their schedule also was to include meetings with the top leadership of the Secretariat of State as well as conferences updating them on current church issues, international collaboration and interreligious dialogue, the press office said.

Some of their time will be spent in groups organized according to the continent where they are ministering, the Vatican said. They also were to meet with some heads of Vatican offices and with ambassadors representing their countries at the Vatican.