Earlier this week, regional mediating body IGAD (Intergovernmental Authority on Development) endorsed an agreement by the warring parties in South Sudan to delay the formation of a power-sharing government for a further six months. The original eight-month period is ending with little visible progress towards the implementation of key provisions of a peace deal agreed last September between rival camps headed by President Salva Kiir and former rebel leader Riek Machar.

Read more: South Sudan rivals delay forming unity government 

In an interview with DW, the US ambassador to South Sudan, Thomas Hushek, said the Trump administration wants to see the two sides implement the peace deal without delay. They should not waste the additional time they have been given but should "use the six months wisely and actively accomplish all the remaining tasks that need to be done during the transition period and even start thinking beyond."

Army unification a major part of the deal

South Sudan broke away from Sudan to become Africa's youngest indepent state in 2011. Just two years later it collapsed into civil war, pitching fighters loyal to President Salva Kiir against those of his former deputy Riek Machar. The death toll is put at around 400,000.

The latest delay in forming a unity government is not expected to have a major impact on the timeline of the peace deal, Hushek said. "We have made a point from the very beginning that even when they consider the delay of the establishment of the transitional government that they be very explicit that this will not cause delay in the elections which come at the end of the transition period."

Under the September 2018 peace deal, the warring parties pledged to implement a number of security arrangements including a so-called cantonment process, under which the armed forces of both sides are to be brought together and later integrated in a single new force. Machar says he will only return from exile in neighboring Sudan once the cantonment process is completed.

Read more: South Sudan rebels sign peace deal

Both camps say a lack of funding has hampered their efforts to achieve the implementation of the deal. Repeated calls for assistance from the international community went unheard, they complain.

Juba government should follow through on pledge

The US administration played a key diplomatic role in ensuring the parties signed the peace deal. The US is South Sudan's biggest aid donor. Ambasssador Hushek says his government currently only funds areas of the agreement such as the humanitarian sector and the bodies monitoring the implementation of the peace deal. "As far as providing assistance directly to the military in terms of security sector reform and in particular the question of cantonment, we cannot fund the upkeep of the military," he told DW "This is something that is off limit for us because this is the military that has, for the past five years, conducted a civil war against its own citizens so we cannot support that."

Hushek said the US would like to see the government of South Sudan release the $100 million (€89 million) it promised to aid the implementation of the peace agreement, in particular the cantonment process.