“The renewed upsurge in fighting represents a callous and blatant disregard of the pledges made during the 25 March 2017 IGAD [Intergovernmental Authority on Development] summit to implement a ceasefire and to facilitate humanitarian access,” said a statement issued overnight by Stéphane Dujarric, Spokesman for the UN Secretary-General.

The statement also urged all sides to cooperate with the UN and other humanitarian actors to ensure safe access to all civilians in imminent danger along the West Bank of the River Nile.

“There can be no military solution to the crisis in South Sudan,” the statement emphasized, expressing hope that regional and international partners will join in encouraging the parties to return urgently to the negotiating table.

The United Nations remains committed to working with the African Union and IGAD to secure a peaceful resolution of the conflict, the statement added.

Meanwhile, the first elements of the Regional Protection Force of the UN Mission in South Sudan (UNMISS) have started to arrive in the country, according to a note issued today by the Mission.

The deployment of the 4,000-strong force was authorized by the UN Security Council in its Resolution 2304 (2016).

UNMISS says the force will provide protection to key facilities in the nation's capital, Juba, and the main routes into and out of the city. It will also strengthen the security of UN protection of civilians’ sites and other UN premises.

The deployment of the force, to be staged over coming months, would free existing UNMISS peacekeepers to extend their presence to conflict-affected areas beyond Juba.

Despite the August 2015 peace agreement, South Sudan slipped back into conflict due to renewed clashes between rival forces – the Sudan People's Liberation Army (SPLA) loyal to President Salva Kiir and the SPLA in Opposition backing former First Vice-President Riek Machar.

At a Security Council meeting earlier this week, David Shearer, the Secretary-General's Special Representative and the head of UNMISS, noted that the opposition has since splintered, making it necessary for UN peacebuilding efforts to be more widely cast than previously. He reiterated the need for a political solution.