Sudanese president in S. Sudan for crisis talk after negotiations fail JUBA, South Sudan, Jan. 6 (UPI) -- The president of Sudan flew to South Sudan Monday to meet with President Salva Kiir to discuss failed peace negotiations between the South and rebel fighters. South Sudanese government leaders and rebel fighters loyal to former Vice President Riek Machar, who was fired in July and accused of trying to stage a coup in December, were in Addis Ababa, Ethiopia, during the weekend working to reach a cease-fire but failed, the New York Times reported. Sudanese President Omar Hassan al-Bashir is the next in a line of regional leaders to visit Juba to show support for peace in the newly formed country. Kenyan President Uhuru Kenyatta and Prime Minister Hailemariam Desalegn of Ethiopia traveled to Juba in late December. Ugandan President Yoweri Museveni made a separate visit. U.S. Secretary of State John Kerry Sunday said the United States also supports peace talks within South Sudan. The negotiations have to be serious. They cannot be a delay gimmick in order to continue the fighting and try to find advantage on the ground at the expense of the people of South Sudan. They have to be credible talks," Kerry said. Meanwhile, Philip Aguer, a military spokesman, said government forces are making progress in recapturing the rebel-held city of Bor, but the army has suffered recent defections. Machar's forces are also making progress on Juba, but "Machar has not the capacity to attack" the capital, Aguer said.