The United States has joined calls for South Sudan to set up a hybrid court to try those who have committed crimes against humanity and war crimes.
The calls have gained traction after President Salva Kiir granted amnesty, last week, to "those who waged war against the government" in the largely ethnic conflict that began in December 2013.
The US State Department has urged the Juba government to set up the hybrid court to ensure justice is served for those who have carried out such mass killings of civilians. The Human Rights Watch has also made similar calls.
"The United States is deeply concerned by the lack of accountability for human rights violations and abuses as well as violations of international humanitarian law in South Sudan," a State Department official said in response to a query by The EastAfrican.
"We call on the government of South Sudan to honour its commitment to establish the hybrid court for South Sudan to provide justice for the victims of abuses committed by government forces and other parties to the conflict."
The US official, who commented on condition of anonymity, added that "any amnesty extended to the opposition and other estranged groups must not absolve it from responsibility for atrocity crimes."
Although President Kiir's pardon was rejected by main rebel leader Dr Riek Machar’s Sudanese People’s Liberation Movement — In Opposition (SPLM-IO), the offer of amnesty has set off alarms that the government has no intention of delivering justice for victims and survivors of grave abuses committed by the South Sudan soldiers and rebels.
A Human Rights Watch specialist in international justice suggested in a recent interview that the African Union should exercise its authority to establish the hybrid court for South Sudan if the government persists in inaction on that initiative.
"If the African Union is committed to justice for atrocities in South Sudan, as the work of its own Commission of Inquiry would suggest, the AU may not have another option except to create the hybrid court," HRW's Elise Keppler said.
A nearly two-year-long investigation by an AU special commission concluded in 2015 that "those with the greatest responsibility for the atrocities at the highest level” should be held accountable for their crimes.
A peace agreement signed that same year by South Sudan's warring parties provided for the establishment a hybrid court that would consist of both international and South Sudanese judges. That deal gives the AU clearance to institute the court on its own.
And although the AU has sought in the past to shield African leaders from international justice, the US and Human Rights Watch are lauding AU's push to launch a hybrid court to try crimes in South Sudan.
"We also support the African Union’s advance efforts to set up the court’s core functions," the US State Department official said in an email to The EastAfrican.
The AU drafted a memorandum of understanding as well as a statute that would enable the court to operate with the cooperation of South Sudan's government.
But while South Sudanese ministers expressed their support last December, "since then you have silence," Ms Keppler said. The memorandum remains unsigned by South Sudan.
The AU's apparent reluctance to create the court unilaterally may reflect concern that the tribunal would probably not be able to operate effectively without the government's cooperation.
Leaders in Juba could frustrate prosecutions by withholding evidence and doing little to dispel a prevailing climate of intimidation and fear that would likely prevent at least some witnesses from giving testimony.
South Sudan has a history of protecting suspected perpetrators of international crimes from prosecution, HRW points out. A de facto blanket amnesty was extended after the 22-year war that ended in 2005 and resulted in South Sudan's breakaway from Sudan.
"South Sudan’s history of unaddressed abuses in conflict and even in relative peacetime, following inter-communal violence, has resulted in anger and ethnic divisions that undoubtedly fuelled the brutality that the South Sudanese have endured in the past year," HRW states.
The watchdog further notes that a hybrid court must include "a majority of international judges and a robust contingent of international prosecutors, investigators and other staff" if it is to function successfully.
In addition to a "significant lack of independence and capacity of South Sudanese prosecutors," the country's own judges often bow to internal political pressures, the rights group notes.
The hybrid court would also have to be based outside South Sudan, at least initially, in order to limit attempts to render it toothless, HRW suggests.
An international tribunal of this sort would likely prove costly to operate, with funding totals for some similar bodies having risen above the $200 million mark, Human Rights Watch observes.
Because contributions for sustaining hybrid mechanisms are made on a voluntary basis, "it has proven immensely difficult to maintain adequate funding for operations, and court officials have had to devote massive amounts of time to fundraising," HRW recounts.
The International Criminal Court already exists and has the potential capacity to put accused South Sudanese figures on trial. But the government is not a signatory to the treaty that established the ICC. For the court to intervene, it requires invitation from the Juba government or upon a decision by the United Nations Security Council to refer cases to the ICC.
Due to divisions among its five permanent members, the Security Council has been reluctant in the past to take such a step.
A troika consisting of the US, the United Kingdom and Norway, which has taken the international lead in seeking to end South Sudan's civil war, has only expressed concern that the developments towards South Sudan's peace may not prove "realistic or sustainable."
The troika in a statement issued two days after Mr Kiir granted the rebels amnesty, did not mention the issue of the hybrid court that is part of the ongoing negotiations to end the five-year civil war.
"Given their past leadership failures," the troika added, "South Sudanese leaders will need to behave differently and demonstrate commitment to peace and good governance."
A UN human rights official has been outspoken in condemning atrocities in South Sudan and calling for them to be prosecuted.
Citing "horrific crimes" involving the killing in April and May of at least 232 civilians at by government-backed troops, UN High Commissioner for Human Rights Zeid Ra'ad al-Hussein issued a demand last month.
"There must be consequences," he said "for the men who reportedly gang-raped a six-year-old child, who slit the throats of elderly villagers, who hanged women for resisting looting, and shot fleeing civilians in the swamps where they hid."
But South Sudan Deputy Information Minister Mrs Lily Albino Akol said on Monday that President Kiir's amnesty was appropriate and aims at creating a conducive environment for the implementation of the peace agreement.
"The President has the right to issue an amnesty when it is appropriate and it is the right thing to do," Mrs Akol was quoted saying by a local Eye Radio in Juba.
"We are not necessarily bound by what other entities that are not part of us think" she added responding to calls to prosecute those who have committed atrocities.
--Additional reporting by Joseph Oduha.