ADDIS ABABA, Dec. 22 (Xinhua) -- The African Union (AU) welcomes the peace agreement signed by South Sudan's government and rebel groups, the chairperson of the commission of the AU has said.

"Today's Agreement marks a critical first step in the efforts to end the senseless conflict and carnage that has been unfolding in South Sudan since December 2013," Moussa Faki Mahamat said Thursday in a statement.

The Agreement on Cessation of Hostilities, Protection of Civilians and Humanitarian Access was signed during the Intergovernmental Authority on Development (IGAD)-led Revitalization Forum that opened in Addis Ababa on Dec. 17.

While welcoming the first step, Mahamat stressed that the true test of the genuineness of the parties' commitments lies in the full and effective implementation of their pledge to end violence and uphold the most basic tenets of international humanitarian law.

"The people of South Sudan, who have endured so much pain and suffering, are investing great expectation in the faithful implementation of this Agreement. They desperately need and deserve respite from war, especially as they enter this festive Christmas season, and look with rekindled hope towards the New Year," he said in his statement.

They should build on this important achievement and continue to make the necessary compromises without which the revitalization process cannot succeed, Mahamat said.

He reiterated the AU's appreciation to IGAD and leaders of the region, for their commitment and steadfastness, saying their continued leadership is critical to take forward the peace process.

South Sudan descended into violence after a political dispute between President Salva Kiir and his former deputy turned rebel chief Riek Machar led to split within the army, leaving soldiers to fight alongside ethnic lines.

A 2015 peace agreement aimed at ending the conflict was weakened after the outbreak of renewed fighting in July 2016 forced the opposition rebel leader Machar to flee the South Sudanese capital of Juba.