Violence erupted between youths from two rival ethnic groups in the camp.
A recent report has revealed that the conflict-riven country is failing the younger generation.
A report from the group cited the discovery of mass graves, among other things.
Yet President Salva Kiir told regional African leaders at the ceremony that he still had "serious reservations."
The warring sides also agreed to abide by a ceasefire deal signed in January 2014 but frequently violated.