Interim Prime Minister Isaac Zida vowed to extradite ousted leader Blaise Compaoré and investigate abuses committed during his 27-year reign.
The retired diplomat's nomination was announced just a few hours before officials signed a transition charter to guide the country towards elections scheduled for 2015.
Military officer Isaac Zida has emerged from the shadows to declare himself interim head of state amid ongoing protests in Burkina Faso.
Thousands of protesters flooded the streets of Ouagadougou on Sunday to express outrage over the declared interim leadership of Lieutenant-Colonel Isaac Zida.
After violent protests ousted President Blaise Compaoré, Burkina Faso's military issued a declaration in support of Lieutenant Colonel Isaac Zida's claim to authority.