Burkina Faso's interim president Michel Kafando, who was deposed last week during a coup, will be returned to office on Wednesday, putsch leader General Gilbert Diendere told AFP on Tuesday.

The return of "Kafando is already a done deal. The (African) heads of state arrive tomorrow (Wednesday) to put him back in office," Diendere said.

His remarks were made after days of marathon talks in Nigeria's Abuja between his junta and the army aimed at ending the crisis that had been expected to result in a deal late on Tuesday.

Earlier, West African leaders from ECOWAS (the Economic Community of West African States) had announced they would return to the capital Ouagadougou on Wednesday to "restore Michel Kafando (to his role) as interim president of Burkina Faso" and to initiate a dialogue "among all stakeholders" in the crisis.

"Theoretically, it is me who will welcome them (at the airport) tomorrow and Kafando will go with them after that," said Diendere, head of the powerful Presidential Security Regiment (RSP).

Kafando and interim prime minister Isaac Zida were seized last Wednesday by presidential guards, but later released.

Diendere is known as close to ousted strongman Blaise Compaore, who was deposed during a popular uprising in October 2014.