Media reports say at least 25 people have been killed in the latest wave of ethnic clashes, which began on Friday in Upper Nile state.
In a statement issued by his spokesperson, Mr. Ban called on "all groups to find peaceful means of settling their differences.
"He also calls on the Government of South Sudan to re-double its efforts to ensure the protection of civilians and to work with UNMIS [the UN Mission in Sudan] and the United Nations Country Team in strengthening security mechanisms, resolving the root causes of the tensions and addressing the humanitarian situation.
"Abatement of violence and intertribal reconciliation in the south are vital to the forthcoming elections in 2010 and the subsequent referendum in 2011."
The UN has become increasingly concern by ethnic-based violence in southern Sudan this year, with at least 100 people killed just last month in Jonglei state.
Published by Mike Hitchen i On Global Trends, world news, analysis, opinion
Putting principles before profits
UNMIS Sudan
Putting principles before profits
UNMIS Sudan