UNITED NATIONS (AP) — The U.N. secretary-general says he is looking into ways that perpetrators of widespread human rights abuses in the South Sudan conflict can begin to be held accountable.

In his latest report released Thursday on the fighting that threatens the future of the world's youngest country, Ban Ki-moon says he has asked his office to explore "options for the establishment of criminal accountability and transitional justice processes ... to address the gravity and scope of the serious human rights atrocities committed in the country since the beginning of the crisis."

He also called on the African Union's security council to "urgently" consider a report which is expected to reveal those responsible for atrocities committed.

The AU has said it is postponing the release of its report so it won't affect efforts toward a comprehensive agreement to end the crisis. Peace talks are expected to resume in neighboring Ethiopia later this month.

Ban urged South Sudan President Salva Kiir and rebel leader Riek Machar to make the compromises necessary to end the fighting peacefully, saying they "can no longer hold the fate of the country hostage to their personal ambitions."

Kiir's office last week said the government is struggling with the idea of sharing power with rebels led by a former vice president, Machar, who is likely to return to that post if a unity government is established.

Although the warring sides have signed many peace agreements, none has held. Tens of thousands have been killed, 1.5 million people have been displaced and a half-million people have fled the country, which split from Sudan in 2011.

It is widely believed that the political rivalry between Kiir and Machar has fueled the conflict, which often has been on ethnic lines.

Ban's latest report urges the international community to make clear to South Sudan's leaders "there are consequences for those who continue to undermine the peace effort."

Ensuring accountability for human rights abuses committed during the conflict will be a challenge. Ivan Simonovic, the U.N. assistant secretary-general for human rights, told reporters after a recent visit to the oil-rich east African country that 70 percent of the police force is illiterate and there are only 100 to 200 judges and a limited number of prosecutors. He said outside help would be needed.