U.N. Secretary-General Ban Ki-moon is calling for a near doubling of the international peacekeeping force in South Sudan amidst spiraling violence. On Monday, Ban asked the Security Council to send up to 5,500 more troops.

U.N. Secretary-General Ban Ki-moon: “The world is watching all sides in South Sudan. Attacks on civilians and the U.N. peacekeepers deployed to protect them must cease immediately. The United Nations will investigate reports of grave human rights violations and crimes against humanity. Those responsible at the senior level will be held personally accountable and face the consequences, even if they claim they had no knowledge of the attacks.”

The Security Council is due to vote on Ban’s proposal today. South Sudan’s violence erupted earlier this month when President Salva Kiir accused his former deputy, Riek Machar, of mounting a coup. On Monday, Machar said the release of opposition leaders is a precondition for talks.

Riek Machar: “We are ready to start dialogue as soon as my comrades under detention there, SPLM leaders, are released and evacuated to a neutral ground, preferably Addis, because these are the people who will engage in the dialogue. We want a peaceful settlement of this conflict. We do not want our people to be subjected to a lot of suffering. They have already suffered enough. We want peace.”

Hundreds have been killed and thousands have sought refuge at U.N. facilities to escape the fighting.