Kenyan and pro-government forces captured the port city of Kismayo, one of the last strongholds of al-Shabaab in Somalia.
Augustine Mahiga, U.N. special envoy for Somalia, said in a briefing from Nairobi that Somalia was moving in the right direction after years of internal conflict.
"It may be more difficult, it may be more challenging, (but) we have moved from transition to transformation which entails peace building (and) around it is state-building," he said.
Somali leaders recently picked a president and members of the legislative assembly, ending a formal political transition period. Prior to that, there hasn't been a functioning central government in Mogadishu since the early 1990s.
The envoy warned, however, that the declining influence of al-Shabaab didn't mean the threat was eliminated.
"They do what they are best at: terrorist bombs, devices, suicide bombs, roadside bombs," he said of al-Qaida's affiliate in Somalia. "That is likely to continue."