Somali leaders agreed to a set of measures that would mark the formal end to the country's transitional government.
Somali President Sharif Sheikh Ahmed last week signed a national security plan that outlines long-term issues for security and justice sector reform in the country. In July, leaders in Mogadishu agreed to the terms of a national constitution.
In a statement issued through his spokesman, Ban expressed concern about outstanding measures left to be resolved before the mandate for the transitional government ends Aug. 20.
"The secretary-general is seriously concerned about delays in the selection of the new Somali Parliament, and recent acts of intimidation and violence which should not continue or be allowed to threaten the successful conclusion of Somalia's transition," the statement read.
Augustine Mahiga, U.N. special envoy to Somalia, has said seats on the new assembly shouldn't become "commodities."
Somalia last had a functioning central government in 1991.