Haley, the most senior US administration official to visit Africa, was in Juba to meet with South Sudanese civilians affected by the nearly four-year war...
Haley, the most senior US administration official to visit Africa, was in Juba to meet with South Sudanese civilians affected by the nearly four-year war and has traveled on to Kinshasa as part of a three-nation Africa tour.
"A group of several hundred protesters approached the site", the US mission said. "The group was not protesting Ambassador Haley's visit, but rather South Sudanese President Salva Kiir."
"Diplomatic security agents determined that the site was no longer secure and escorted Ambassador Haley and her traveling party out of the site, cutting the event short by a few minutes," the mission added.
After meeting with Kiir, Haley said the United States was disappointed with South Sudan after investing $11 billion (nine billion euros) in the country under Kiir's leadership.
"We are disappointed by what we are seeing, this is not what we thought we were investing in. What we thought we were investing in is a free and fair society where people could be safe, and South Sudan is the opposite of that," Haley told local radio.
"But we are not going to give up on the South Sudanese people, we are here to fight for them, we are here to help, to do whatever we have to, to make peace and security become a permanent part of South Sudan," she added.
There was no comment from Kiir after the meeting.
Haley said last month she wanted to salvage a tattered 2015 peace deal that collapsed in July last year, as regional mediators launch a fresh bid to "revitalise" the agreement.
South Sudan won independence in 2011 with strong support from the United States.
The conflict erupted in December 2013 when Kiir accused his former deputy, Riek Machar, of plotting a coup.
Initially a war pitting ethnic Dinka supporters of Kiir against Machar's Nuer people, the conflict has since metastasised to include different groups and local interests.
Last week the regional Inter-governmental Authority on Development (IGAD) said it had finished consultations with a wide range of parties and is expected to announce a new round of peace talks.
Brian Adeba of the Enough Project advocacy group that closely follows the South Sudan conflict, told AFP that the new peace push came as government was particularly "intransigent to peace".
"It believes it has won the war, it has taken a lot of territory and the opposition is not in a position to retaliate," he said.
Haley began her Africa tour in Ethiopia, which is leading the latest peace efforts in South Sudan, where the United Nations has deployed a 14,000-strong peacekeeping mission.
In the Democratic Republic of Congo, Haley is expected to press President Joseph Kabila to agree to a timetable for elections.