The Secretary General of the Francophonie organisation which groups together French-speaking nations around the world, says that 85 per cent of French speakers around the world will be in Africa by the year 2050, according to projections.
He was speaking as representatives from 75 nations gather in Kinshasa in the Democratic Republic of Congo for the 14th Francophonie summit, which kicks off tomorrow.
There are currently an estimated 220 million French speakers around the world, making French the ninth language on the planet, but Diouf said that by 2050, there could be as many as 715 million Francophones.
The decision to hold this year's summit in Kinshasa has been controversial, given the government's poor democratic credentials and human rights record, and fresh fighting in the east of the country.
Only this week French president François Hollande described the political and human rights situation in DRC as "unacceptable", earning a rebuke from the Kinshasa government.
The three day meeting will break DRC president Joseph Kabila's relative diplomatic isolation and millions of euros have been spent sprucing up the city of 10 million people to ready it for the summit.
Among subjects to be discussed is the crisis in Mali, which is a member state, and where several countries would like to see a military intervention to oust the al Qaeda-linked extremists who took over the north in March.