Displaced civilians taking refuge at the Tomping base of the UN Mission in South Sudan (UNMISS), in the wake of fresh clashes in Juba between soldiers of the Sudan People's Liberation Army (SPLA) and the SPLA in Opposition (SPLA-IO). (UN Photo/Beatrice Mategwa)

JUBA, Aug. 1 (Xinhua) -- A Top United Nations relief official is due in South Sudan for a three-day visit this week to see first-hand the appalling humanitarian situation and call for urgent action to alleviate suffering, the UN has said.

A statement from the UN Office for Coordination of Humanitarian Affairs (OCHA) said Stephen O'Brien, UN Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator, will visit the youngest nation from Aug. 1 to 3.

"During the three-day mission O'Brien will meet with people affected by the humanitarian crisis, senior government officials and humanitarian partners," the statement said.

Tens of thousands of civilians have been displaced after recent fighting in Juba and Wau, there is escalating food insecurity and malnutrition across the country, and a cholera outbreak has erupted in Juba and Jonglei.

Prior to the eruption of fighting in Juba on July 7, the humanitarian situation in South Sudan was already dire, with unprecedented levels of food insecurity and one in five people displaced.

The 2016 Humanitarian Response Plan for South Sudan is currently just 40 percent funded as slightly over 500 million U.S. dollars have been received out of 1.3 billion dollars required and additional resources are urgently required to respond to the growing needs.

The visit comes after the UN Security Council on Friday extended for two weeks the UN Mission in South Sudan (UNMISS), allowing time for its membership to consider options on adapting the operation's mandate amid renewed violence in the world's youngest country.

With the mandate of UNMISS set to expire in 48 hours, the Council unanimously approved a short extension -through Aug. 12, by a resolution that also authorized the Mission "to use all necessary means to carry out its tasks."

The UN action comes as deadly clashes between rival factions loyal to President Salva Kiir and First Vice-President Riek Machar have, since early July, sent thousands of civilians fleeing the capital, Juba.

UNMISS compounds and civilian protection sites have been attacked. The UN refugee agency has reported that thousands of South Sudanese, mostly women and children, have crossed into Uganda since fighting erupted, including an estimated 8,337 refugees on July 21, setting a single-day record since the influx began in 2016.