GENEVA (Reuters) - U.N. agencies increased their 2017 appeal for South Sudan’s refugees on Monday, saying they needed at least $1.4 billion to help alleviate “unimaginable” levels of suffering.

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The U.N. refugee agency and the World Food Programme had earlier asked for $1.2 billion to support more than 1.8 million people fleeing fighting. But even that was only 14 percent funded, the agencies said in a joint statement.

“The suffering of the South Sudanese people is just unimaginable ... They are close to the abyss,” WFP Executive Director David Beasley said.

Two years after its independence, South Sudan plunged into conflict in December 2013 after rivalry between President Salva Kiir and his then-vice president, Riek Machar, exploded into violence.

A 2015 peace deal was signed but the terms were never fully respected. Lingering suspicions between Machar and Kiir triggered a fresh bout of fighting in July 2016 and violence has since spread to large areas of the country.

The conflict has led parts of the oil-producing country into famine and paralyzed public services.

Other anti-government groups have also emerged since the conflict erupted. Some have fought each other.

On Saturday, seven opposition groups, including that of Machar, said they had agreed to work closely in their bid to oust Kiir’s government.

Last week, Kiir fired his army chief Paul Malong, raising fears of armed confrontation. Malong has said he had no intention of staging a revolt against Kiir’s government.

Beasley said the number of those displaced by fighting stood at 3.8 million, and that 5.5 million people are facing hunger, while the onset of the rainy season was expected to make many roads unusable, making it harder for help to reach them.

“I am deeply alarmed and saddened by the widespread hunger and misery suffered by the South Sudanese people due to the ongoing conflict. The situation in the country is bleak and getting frankly worse,” said Beasley, who added he would be returning to South Sudan later this week.

“This crisis is man-made and is fueled by violence. There is now a real danger that famine, which has already been declared in parts of the former Unity State, could spread to other areas.”