Washington (AFP) – The United States Tuesday ordered all non-emergency embassy staff to leave South Sudan amid an outbreak of fierce fighting and stressed the onus was on the country’s leaders to end the violence.

“The Department of State ordered the departure of non-emergency U.S. government personnel from South Sudan because of ongoing political and social unrest,” it said in a statement.

The U.S. mission in the capital Juba would also suspend normal operations for the time being.

As rival troops were locked in fresh battles, State Department deputy spokeswoman Marie Harf said: “The onus is certainly on the parties themselves to take a step back here and avoid further violence.”

President Salva Kiir on Monday accused soldiers loyal to his arch-rival, former vice president Riek Machar, of staging a coup attempt in the oil-rich but deeply impoverished nation.

But Harf told journalists it was “premature to say what sparked the violence” saying the situation “is fluid.”

“Until we have a better sense of the situation that’s unfolding, I’m not going to characterize it one way or the other. We’ll just keep looking at the facts,” she said.

The fighting in the world’s youngest nation has set off alarm bells in the international community, with the United Nations urging the warring groups to refrain from ethnic violence.

The US special envoy to South Sudan, Donald Booth, spoke with Kiir Tuesday calling “for a peaceful resolution of the situation, for an end to the violence,” while also underscoring “the importance of the rule of law (and) avoiding arbitrary arrests,” Harf said.

He “also talked about ways to get South Sudan back on track towards realizing the vision that their country set forth for itself in independence.”

The updated U.S. travel warning also “warns U.S. citizens against all travel to the Republic of South Sudan and recommends that U.S. citizens currently in South Sudan depart immediately.”

Those who choose to stay “should review their personal security situation and seriously reconsider their plans to remain,” it adds.

Washington was also talking with South Sudanese officials on providing help to get U.S. nationals out of the country, and was calling on Juba to “open points of entry” including the airport, Harf said.

AFP Photo/Rolla Hinedi