Pope Francis will receive United Nations Secretary-General Ban Ki-moon at the Vatican on Friday while the UN chief is in Rome for a yearly meeting of all the heads of international agencies.

Ban's press spokesman Stéphane Dujarric told Vatican Radio on Thursday it is not the first time the U.N. Secretary General will meet Pope Francis - or the man he succeeded, Pope Benedict XVI.

"He hosted Pope Benedict in New York during his visit to the United Nations which was a great honor for the Secretary General and last year he met with Pope Francis here in the Vatican.

"What makes this visit special is that Rome is hosting, today and tomorrow, the annual meeting of all the heads of the UN agencies, so some 50 senior U.N. officials."

These include the head of the World Bank and the World Health Organization who are meeting Ban "and he's bringing his whole delegation for a meeting with Pope Francis."

Dujarric said countries they will touch upon will include South Sudan, Syria and Central African Republic.

"I think the Holy See and the United Nations may not agree on a number of issues on the global agenda, but I think where they do agree, where the Secretary General and the Holy Father meet, is on the fight against poverty, on the fight against inequality, against exclusion, against forgetting those who are suffering," said the U.N. spokesman.

Earlier this week, Ban was in Juba, South Sudan where he appealed for peace between warring sides so that much-needed humanitarian aid can reach the suffering population and allow farmers to plant food.

"What you have in South Sudan is a man-made humanitarian disaster and it is because the President Salva Kiir and the former Vice President Riek Machar have had a falling out, [for] which the term is probably too simple," said Dujarric.

"But these two men who were brothers in arms for years, to fight for the independence of their country, are now fighting against each other."