"The situation in the capital Juba has become stable and peaceful, all troops returned to their barracks," Ateny said.
An armed ethnic conflict erupted in South Sudan in December 2013, 1.5 years after the nation gained independence from Sudan, when Kiir accused First Vice President Riek Machar of preparing a military coup. Over a million people have fled their home amid the conflict.
In August 2015, Kiir and Machar signed a peace deal that envisaged the formation of the Transitional Government of National Unity.
Renewed fighting broke out last week and over 300 people have already lost their lives in the clashes, according to media reports. On Monday, both Kiir and Machar ordered their forces to cease fire.