Mr Dujarric said the UN chief spoke earlier in the day to President William Ruto of Kenya and with the Chairperson of the African Union (AU) Commission, Moussa Faki.
The UN Secretary-General, António Guterres, will hold a virtual meeting on Thursday with the AU Chairperson, the Secretary-General of the Arab League, the Executive Secretary of the East African bloc, IGAD, and other leaders on the crisis in Sudan.
UN spokesperson Stephane Dujarric told journalists at the UN headquarters on Wednesday that Mr Guterres would hold the meeting together with other relevant organisations, to discuss ways the international community could help end the violence and restore order inside Sudan.
Mr Dujarric said the UN chief spoke earlier in the day to President William Ruto of Kenya and with the Chairperson of the African Union (AU) Commission, Moussa Faki.
"Obviously, he will continue to be fully engaged, making phone calls, trying to secure a 24-hour ceasefire, which will enable a much-needed reprieve to all affected civilians in Khartoum," he said.
The UN Special Representative in Sudan, Volker Perthes, also continued engagement with parties on the ground, key Sudanese leaders and Member States, in trying to secure an immediate de-escalation in the fighting.
The crisis between the Sudanese armed forces and formerly allied Rapid Support Forces (RSF) paramilitaries emerged as the country appeared to be returning to the path towards democratic transition. The sides are at odds over the process of restoring civilian rule.
The deadly clashes erupted on Saturday. An initial 24-hour ceasefire, announced for 6 p.m., local time, on Tuesday, collapsed within minutes of the deadline.
The parties committed to a new 24-hour truce on Wednesday, also beginning at 6 pm local time, but some international media reported that shelling had continued.
The UN, AU and IGAD - known as the Trilateral Mechanism - issued a statement appealing to the sides "to create necessary conditions during this period for the civilians to seek safe shelter, food and medical care."
Mr Dujarric said the continued heavy fighting is having devastating consequences for civilians, as well as UN staff and other members of the international community.
"We reiterate to the parties to the conflict that they must respect international law," he said.
"They are obliged to protect civilians and ensure the safety and security of all United Nations and associated personnel as well as their premises, our assets, and trapped civilians must be able to receive assistance, access essential supplies and evacuated to safer zones as needed."
As the crisis deepens, humanitarians warn that people are running out of food, fuel and other vital supplies, and many urgently need medical care.
"We desperately need a humanitarian pause so that wounded and sick civilians can reach hospitals," Mr Dujarric said, adding "people in Khartoum have been unable to safely leave their homes to buy food and other essential items for days."
He reported that the humanitarian response remains severely hampered, calling for an end to attacks against aid workers and looting of humanitarian facilities.
"Humanitarians must be able to safely carry out their work. Aid agencies must be able to safely move staff and replenish critical supplies," he stressed.
The UN is also worried that Sudan's healthcare system could completely collapse as hospitals need additional staff and supplies, including blood.
The violence and attacks have forced 16 hospitals across the country to close, nine of them in Khartoum alone, Dujarric said, citing the World Health Organisation (WHO). Another 16 hospitals, including in Darfur states, could close soon due to staff fatigue and lack of supplies.
"It goes without saying that we condemn all attacks on health personnel, on facilities and ambulances - which is putting more lives at risk," he said. "These are flagrant violations of international law, and they must stop."
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As fighting rages on in Sudan, humanitarian agencies are also monitoring the arrivals of new Sudanese refugees in neighbouring Chad, a representative of the UN refugee agency (UNHCR) said on Wednesday.
UNHCR's Laura Lo Castro tweeted about a joint mission conducted with the UN World Food Programme (WFP), the UN Children's Fund (UNICEF) and Chad's national commission in charge of refugees, to observe the influx of new Sudanese refugees in the east, "assess urgent needs and agree on [a] response plan".
She said there were an estimated 10,000 to 20,000 new refugees in the first three sites visited.
Any new arrivals will be entering a situation marked by soaring humanitarian needs and chronic underfunding.
Last week, before the military power struggle erupted in Sudan, WEF warned that hundreds of thousands of refugees and internally-displaced people in Chad could face hunger because there was no funding for food assistance beyond this coming May.
(NAN)
