The prolonged border closure had severely disrupted trade between Kenya and Somalia, with miraa farmers and traders among the hardest hit.
The US on Thursday announced the resumption of food distribution in Somalia, weeks after destruction of a US-funded World Food Programme (WFP) warehouse at Mogadishu's port.
Somalia's Parliament has ratified the revised IGAD Treaty, making it the fifth nation to endorse the framework and meeting the two-thirds threshold needed to operationalise the agreement.
The election fever in the region has also hit some of the member states in Somalia with Puntland and Jubaland particularly unhappy with developments in Mogadishu.
Two police officers killed, two others seriously injured in suspected IED attack at Kulun border post on the Mandera-Somalia border, authorities say.
Somalia cancelled all agreements with the UAE on Monday amid tensions over Israel's recognition of Somaliland.