JUBA, South Sudan (AP) -- Violence since mid-December in South Sudan has displaced up to 180,000 people, the United Nations said Monday, as regional leaders intensified efforts to bring South Sudan's president and his main political rival to the negotiating table.
A meeting of East African leaders last week said it "welcomed the commitment" by South Sudan's government to cease hostilities against rebels, but hopes for a cease-fire.
Riek Machar, the fugitive former vice president who now commands renegade troops, instead called for a negotiated cease-fire that includes a way to monitor compliance.
Ethiopia's Foreign Ministry said Monday that a regional bloc known as IGAD has named a Kenyan and an Ethiopian as special envoys who will "spearhead mediation and broker peace" between South Sudan President Salva Kiir and the opposition, the ministry said in a statement. IGAD members must create an environment "conducive" for both sides to participate in direct talks, it said.
In Uganda, a spokesman for the Foreign Ministry said Ugandan President Yoweri Museveni visited South Sudan Monday "in the spirit" of IGAD's diplomatic efforts to forge a political solution in South Sudan.
"The mood among regional leaders, and in Uganda, is that these guys must get to the table and talk," said Fred Opolot, talking about Kiir and Machar.
Uganda's influence is strong in South Sudan, where special forces from the neighboring country have been deployed at the request of Kiir, raising questions about the impartiality of Uganda as a possible mediator in a conflict that many fear could lead to civil war in the world's newest country.
Museveni and Kiir are strong allies. The Ugandan leader is believed to be concerned about the security implications for Uganda of a violent takeover of South Sudan's government.
For years the brutal warlord Joseph Kony, who once operated in the expansive jungle that now falls within South Sudan's territory, was a source of tension between Uganda and Sudan. Sudan's government faced persistent allegations of supporting Kony's rebellion against Uganda's government. Kony was forced to flee, and is thought to have fled to Congo and then Central African Republic, as the south moved closer to independence from Sudan.
South Sudan peacefully broke away from Sudan in 2011 after a decades-long fight for independence, giving Uganda a new sense of border security. Uganda, one of the south's strongest supporters in its quest for independence, denies it has taken sides in South Sudan's latest conflict, saying its forces provided security as Western countries and others safely evacuated their citizens from South Sudan.
Ugandan military spokesman Lt. Col. Paddy Ankunda insisted Monday that Ugandan forces are stationed only at the international airport in Juba, the South Sudan capital, and that their task is to "facilitate evacuation of civilians." But United Nations workers in Juba told The Associated Press that Ugandan troops have been guarding the only bridge that crosses the Nile River.
Although Juba is now calm, unrest persists in other parts of the country.
Col. Philip Aguer, the South Sudanese military spokesman, said Monday that, although there was "no major fighting" over the weekend, tension remained because "Machar has not committed himself to a cease-fire. We've not seen one." Pro-Machar forces still control Bentiu, the capital of oil-producing Unity state, and renegade troops are poised to attack Bor, the contested capital of Jonglei state, according to Aguer.
"There's a force advancing toward Bor," he said.
Although Kiir insists the latest unrest was sparked by a coup mounted by soldiers loyal to Machar late Dec. 15, this account has been disputed by some officials with the ruling party who say violence broke out when presidential guards from Kiir's majority Dinka tribe tried to disarm guards from the Nuer ethnic group of Machar.
South Sudan has been plagued by ethnic tension and a power struggle within the ruling party that appears to have escalated after Kiir sacked Machar as his deputy earlier this year. Machar has criticized Kiir as a dictator and says he will contest the 2015 presidential election.
The U.N., South Sudan's government and other analysts say the dispute is political at its heart, but has since taken on ethnic overtones. The fighting has killed more than 1,000 people, according to the U.N.
Muhumuza reported from Kampala, Uganda. Associated Press reporter Elias Meseret in Addis Ababa, Ethiopia, contributed to this report.