The Africa Cup of Nations is set to be increased to 28 teams from 24, CAF president Patrice Motsepe said on Sunday.
The surprise announcement was made at a press conference following an executive committee meeting with Motsepe saying it was evidence of his organisation's "commitment to world-class football with the best African players from all over the world returning to compete on the continent."
But he did not explain how the format will work with four extra teams, nor when it would be implemented.
The last four Cup of Nations finals have all had 24 participants, increased from 16 in 2019.
Motsepe insisted the 2027 finals would go ahead as planned in Kenya, Tanzania and Uganda.
There is to be another Cup of Nations tournament in 2028, after which the continent's showpiece event will be held every four years.
CAF is to introduce a Nations League annually from 2029 with a 16-team final tournament held every two years, he added.
"We have to stop this thing of African fixtures not being predictable, consistent and reliable. We must develop football in East Africa, which is an area of much potential," Motsepe said.