US warns South Sudan warring parties on ceasefire

Civil war erupted in South Sudan in 2013 after a power struggle between President Salva Kiir -- who is ethnic Dinka -- and his former deputy Riek Machar from the Nuer community (AFP Photo/Samir BOL)

Washington (AFP) - The United States on Tuesday warned both sides fighting in South Sudan to down arms or face sanctions that have already been authorized by the UN Security Council.

A truce aimed at ending the brutal civil war between government and rebel forces in South Sudan, the world's newest nation and one of its most troubled, came into effect on Saturday.

But rebel leader Riek Machar has already accused President Salva Kiir's forces of breaking the ceasefire and the peace process is in danger, while 200,000 civilians are sheltering in UN bases.

The US State Department did not attribute blame for the latest fighting but demanded that it cease and reminded the warring parties that the Security Council has already approved sanctions.

"The United States condemns the recent fighting in Jonglei State and Upper Nile State in South Sudan," deputy spokesman Mark Toner said.

"Anyone acting to spoil the peace agreement implementation will face consequences." A UN Security Council resolution has authorized targeted sanctions and an arms embargo if fighting continues.

Fighting erupted in December 2013 -- two years after South Sudan's hard-won independence -- when Kiir accused Machar of planning a coup.

This unleashed a wave of killings that has split the young country along ethnic lines and embarrassed the United States, which pushed hard for its international recognition.

At least seven ceasefires have already been agreed and then shattered within days or even hours, while 2.2 million people have been driven from their homes.