JUBA, May 16 (Xinhua) -- The UN top relief official wrapped up a two-day visit to South Sudan on Wednesday, calling all warring parties to cease hostilities and protect humanitarian workers and civilians.

Mark Lowcock, the UN Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator, lamented that ordinary persons are now suffering amidst fresh fighting that has displaced tens of thousands of people in multiple locations across the country.

"The conflict in South Sudan is now in its fifth year. Ordinary people are suffering on an unimaginable scale. The peace process has so far produced nothing. The cessation of hostilities is a fiction. The economy has collapsed," Lowcock said in a statement issued at the end of his visit.

Lowcock who arrived in Juba on Tuesday held talks with senior government officials, members of SPLA-in Opposition, humanitarian agencies, and partners. He also visited people affected by the crisis in Juba, Yei Town and Mundu.

"Belligerents use scorched-earth tactics, murder and rape as weapons of war. All these are gross violations of international law. Seven million people need humanitarian assistance in 2018. And things are simply getting worse," he said.

The UN relief official said ending the violence in the world's youngest nation is the first and single most important thing needed to alleviating human suffering in South Sudan.

According to the UN, about 4.3 million people have been displaced, including more than 1.76 million who are internally displaced and about 2.5 million in neighboring countries.

Lowcock said displaced people are more vulnerable to threats to their safety, health and livelihoods. "Despite a multitude of challenges, humanitarians are saving lives and protecting people," said Lowcock.

He said about 7 million people, more than one in two across the country, will need humanitarian assistance in 2018 due to compounding effects of widespread violence and insecurity and a deteriorating economy.

Lowcock, who also met with relief agencies whose staff and operations have been affected by insecurity and paid tribute to the bravery of aid workers across the country, said the humanitarian workers need rapid, safe, unhindered access to all people in need.

"Aid agencies are subject to harassment, extortion, looting, kidnappings, killings, predatory fees and levies and other blockages across the country -- perpetrated by all parties to the conflict," he said.

He described South Sudan as "one of the most dangerous places in the world to be a humanitarian worker as crimes are being committed against aid workers, with apparent impunity.

"There needs to be accountability, and the Government - because it is the Government, and this is a responsibility of Governments everywhere -- has the prime responsibility for that," Lowcock said.

The number of aid workers killed in South Sudan since conflict broke out in December 2013 reached 101 this month, according to the UN.