Mohamed Hussein Roble officially assumed office as Somalia's prime minister on Sunday following his appointment by President Mohamed Farmaajo.

The ceremony took place at the presidential palace in the nation's capital Mogadishu.

Roble, a humanitarian worker and a newcomer to Somalia's political landscape replaced Ali Khaire, who was voted out of office by legislators in a no-confidence vote in July.

His appointment came after regional leaders agreed on a revised model for presidential and parliamentary elections.

"I thank H.E President @M_Farmaajo for entrusting me with the massive mandate to lead the #Somali Government at a critical juncture and parliament for the subsequent approval," Roble tweeted.

Roble also expressed his gratitude to Mahdi Gulaid for his stewardship of the interim government and a "well organized" handover.

Roble had pledged to create an effective government which will address some of the key challenges facing the Horn of Africa nation, among them holding fair presidential and parliamentary elections.