ADDIS ABABA, Ethiopia (AP) — Peace talks between South Sudan's two warring factions resumed in the Ethiopian capital of Addis Ababa on Tuesday, as the United Nations warned of "the potential for a catastrophic situation" for millions in need of food and other aid.

The talks, mediated by the regional organization known as IGAD, are trying to bring a halt to the conflict that began in mid-December. The mediators are consulting with both sides on "the conduct of a political dialogue (toward) national reconciliation and healing," said an IGAD statement.

Despite a cease-fire and international calls for calm, the factions have continued to fight for control of strategic towns in one of the world's poorest countries.

Mediators are "gravely concerned" about the fighting and urged the international community to put pressure on both sides "to stop the war," said the statement.

The politically fueled ethnic violence continues between forces loyal to President Salva Kiir and rebel soldiers loyal to dismissed former vice president Riek Machar, despite a Jan. 23 cease-fire agreement.

The peace talks resumed as the United Nations sounded an alarm about desperately needed aid that continues to be delayed on the ground.

Nearly 5 million people need humanitarian assistance, and 3.7 million of them are at high risk of food insecurity, John Ging, the director of U.N. humanitarian operations, told reporters in New York. He visited South Sudan last week.

He said 700,000 people are displaced within the country, and 67,000 continue to shelter in eight U.N. mission bases there.

"The newest country in the world is now imploding," Ging said. He expressed hope in the peace talks, saying the people of South Sudan "waited too long for independence, only to have it snatched from them."

One major challenge in delivering aid is the lack of respect for U.N. humanitarian staff, convoys, facilities and supplies, he said. One day during his visit, 50 aid trucks were delayed at checkpoints around the country.

"This is not acceptable," Ging said. He added, "The government of South Sudan knows perfectly well the distinction between humanitarian aid and peacekeeping."

The other major issue is the lack of international funding, the U.N. official said. Just 25 percent of the almost $1.3 billion humanitarian appeal for the country has been funded.

Aid workers are in a race against time to get enough supplies into place before the rainy season begins, which would mean more money that could be used for food and other aid being diverted for more expensive delivery by air.

"It's an alarming situation. We're not going to use the word 'famine' right now, but we've got to be prepared," Ging said.

The U.S. State Department said Tuesday it is giving another almost $83 million in aid to people affected by the violence in South Sudan.

• Politics & Government
• South Sudan
• United Nations