The United States vowed Friday that it remained committed to ending the violence in South Sudan, despite evacuating most of its remaining staff from the embassy in Juba.
"Even as we draw down our personnel, we continue to be engaged in and strongly support regional and international efforts to bring the violence to an end," State Department deputy spokeswoman Marie Harf said.
She said that "due to the deteriorating security situation and out of an abundance of caution, the Department of State ordered the departure of most remaining US government personnel from South Sudan. "
The Pentagon sent two KC-130 aircraft earlier Friday from Uganda to South Sudan to "evacuate approximately 20 personnel" from the US embassy in Juba, spokesman Colonel Steven Warren told reporters.
"The two C-130s are now back in Entebbe standing by for any further requests from the State Department," Warren said.
But US ambassador Susan Page remained in Juba, trying to help end the fighting.
Washington also announced Friday an additional $50 million in humanitarian aid, bringing the total US aid funding for refugees and those affected by the fighting to $330 million so far.
Thousands of people are feared to have been killed in the fighting, since it erupted on December 15 pitting army units loyal to President Salva Kiir against a loose alliance of ethnic militia forces and mutinous army commanders nominally headed by his rival former vice president Riek Machar.
The two sides are due to open direct talks aimed at ending the violence in Ethiopia on Saturday.
US special envoy to South Sudan, Donald Booth, is also in the Ethiopian capital working to end the bloodshed.
He was urging the two sides "to reach an immediate cessation of hostilities, allow full and unfettered humanitarian access, and outline tangible steps toward resolving their differences peacefully that can be implemented immediately," a US official told AFP.
"Dialogue is critical to resolving the political crisis at the core of this conflict, and in reconciling the nation."
About 45 troops remain stationed in Juba to provide additional security for the US embassy.
Asked about possible US military support for a UN peacekeeping mission or further evacuations, Warren said: "We have contingency plans in place. We believe we are well postured in the region to provide any type of support that's requested."