Senegal’s new president has appointed firebrand politician and key backer Ousmane Sonko as prime minister in his first act as the West African nation’s leader.

Bassirou Diomaye Faye made the announcement shortly after he was sworn into office on Tuesday, pledging systemic change after years of deadly turmoil under his predecessor, Macky Sall, a political opponent of Sonko Speaking after his appointment, Sonko said he would present Faye with a full list of proposed ministerial appointments for his approval.

Faye took the presidential oath in front of hundreds of officials and several African heads of state at an exhibition centre in the new town of Diamniadio, near the capital, Dakar. Faye, 44, has never previously held elected office. He swept to a first-round victory on a promise of radical reform just 10 days after being released from prison.Lena Sene, an economist based in Dakar, told Al Jazeera that Faye faces a “very difficult” challenge as president.