The pope has urged the world's rich nations to do their "moral duty" by taking serious measures to fight poverty and disease, especially in Africa.
The pontiff's appeal came in a letter written to German Chancellor Angela Merkel, the current duty president of the European Union and the host of a G8 summit scheduled for June 6-8 in the German town of Heiligendamm.
Benedict said he was alarmed by the "inability" of rich countries to help poorer ones deal with poverty and scourges such as the AIDS epidemic in Africa.
"This is not an extraordinary task or a concession that can be put off because of pressing national interests. It is rather a serious and unconditional moral duty," the pope said.
All nations belong to the same "human family", he wrote in the letter, which was written last December but made public by the Vatican on Monday.
Benedict also called on the G8 group of rich countries to cancel the foreign debt of the world's poorest nations so as to allow them to develop their economies freely.
He urged the group to "take measures for a rapid, complete and unconditional cancellation of the foreign debt of highly indebted poor countries and less developed countries".
Merkel, in a response dated February 2, promised to use the German G8 and EU presidencies to push for "progress in the fight against poverty" and for development in Africa.
The Chancellor's answer to the pope's letter was also published by the Vatican on Monday.
Commenting on Benedict's initiative, Vatican spokesman Father Federico Lombardi noted that it disproved the frequently aired theory that the German pontiff was "Euro-centric".
Africa was a constant theme in Benedict's keynote messages at Easter and Christmas and also in his speeches to foreign diplomats in the Vatican, Father Lombardi said.
The 2005 G8 summit in Gleneages. Scotland, pledged to double aid to Africa, add $50bn a year to global aid by 2010 and bring debt relief to 40 poor countries.
Several observers say these promises are not being respected.
