The United Nations says over 2.5 million people in South Sudan are on the brink of famine amid the destructive civil war in the country.

UN emergency relief coordinator Valerie Amos issued the warning on Monday during an international donor conference in the Kenyan capital Nairobi, where the world body launched a 1.8-billion-dollar aid appeal.

The UN official referred to “the continuing widespread devastation and destruction,” in South Sudan and called for restoration of peace in the war-torn country.

According to the UN, 2.5 million people – about 20 percent of South Sudan’s population of 12 million -- are in a state of emergency or crisis, only few steps short of famine. More than half of the country’s population are in need of aid.

The UN predicted that the conflict would worsen in the dry season when military vehicles could move around more easily.

Amos, who recently paid a three-day visit to the African country, added, “The conflict has had a devastating impact on South Sudan but if peace doesn't come quickly, it will also have a significant regional impact.”

Meanwhile, the donor nations in the conference pledged USD 529 million (467 million euros) in aid for South Sudan.

South Sudan plunged into violence in December 2013, when fighting erupted between troops loyal to President Salva Kiir and defectors led by his former deputy, Riek Machar, around the capital, Juba.

The clashes left tens of thousands of South Sudanese dead, and forced almost two million people from their homes. Seven ceasefires have so far failed to end the clashes in the country.

South Sudan gained independence in July 2011 after its people overwhelmingly voted in a referendum for a split from Sudan.