South Sudan president said to be ready for talks with former VP

South Sudan's President Salva Kiir said Monday he is committed to beginning talks with rebel leader Riek Machar, the country's former vice president, to end violence the United Nations said has left 1,000 people dead, according to a senior U.S. official who met Kiir in the country's capital, Juba, earlier in the day.

The development comes as the U.N., which has about 7,000 peacekeepers in South Sudan, mulls increasing their troop numbers to better protect civilians from the escalating conflict. The U.N. Security Council is expected to adopt a resolution on Tuesday approving about 5,000 troops and 280 more police for the peacekeeping mission, unnamed diplomats told Reuters. 

"President Kiir committed to me that he was ready to begin talks with Riek Machar to end the crisis without preconditions as soon as his counterpart is willing," U.S. special envoy to Sudan and South Sudan, Donald Booth, said on a conference call with reporters Monday.  

U.S. Ambassador to the U.N. Samantha Power said Monday evening, following an emergency U.N. Security Council meeting: "The future of South Sudan is in jeopardy, and this moment demands urgent leadership to avoid further bloodshed and to restore stability."

Earlier, Machar told Reuters he was ready for dialogue but added that Kiir must first release his detained political allies. Kiir detained 11 politicians, some of them former ministers, in connection with the "foiled coup." Booth said he visited the detained officials who were "secure and well taken care of."

"These individuals communicated to me their desire and their readiness to play a constructive role in ending the crisis through peaceful political dialogue and national reconciliation," Booth added. "I will be following up to see how the government may utilize this constructive position."

Information Minister Michael Makuei immediately dismissed the demands made by Machar, who was South Sudan's vice president until Kiir fired him in July. 

"There is no way we will release anybody who is accused of a coup d'etat," Makuei told Reuters.

Makuei also dismissed Machar's claims that his rebels have taken over all the major oil fields in Unity and Upper Nile states as "wishful thinking."

The violence began late on Dec. 15. Kiir, an ethnic Dinka, has said an attempted military coup triggered the violence, and the blame was placed on Machar, an ethnic Nuer. Other officials have since said a fight between Dinka and Nuer presidential guards triggered the fighting. 

"For as long as these two individuals are at loggerheads, refusing to sit down with one another, innocent people are being killed on nothing other than ethnic grounds," Power said. 

Western powers and east African states, which want to prevent the fighting from destabilizing a fragile African region, have tried to mediate. But so far, their efforts have been fruitless as clashes entered their second week, reaching the country's vital oil fields and destabilizing a state that only won independence from Sudan in 2011.

"It's not clear exactly how all this started, but it does seem as though ethnic tensions within the military, within the republican guard, helped to fuel the violence that is now spiraling almost out of control," Iain Levine, program director at Human Rights Watch, told Al Jazeera on Monday. 

Hundreds of people have been killed, with reports of summary executions and ethnically targeted killings, raising fears of a civil war. 

"All of the elements that could allow it to happen are there — you have 200,000 armed men in the SPLA (South Sudan's army). You only have 7,000 U.N. peacekeepers; you have decades and generations of tensions between ethnic groups, particularly the Nuer and the Dinka," Levine said. "So the first and the most political thing that can be done in a sense is to ensure that both (Kiir and Machar) stand back and take time to resolve their problems politically and not through the kind of conflict and attacks on civilians we've been seeing this week."

Meanwhile, U.N. Secretary General Ban Ki-moon said Monday that "the world is watching all sides in South Sudan." 

"Attacks on civilians and U.N. peacekeepers deployed to protect them must cease immediately," Ban said. "The United Nations will investigate reports of grave human rights violations and crimes against humanity. Those responsible, at the senior level, will be held personally accountable and face the consequences."

Two Indian peacekeepers and at least 11 Dinka civilians were killed last week in an attack by about 2,000 armed youths on a U.N. peacekeeping base in Jonglei state.

Both Machar and Kiir have denied opposing claims that they are stoking ethnic tensions in a country boasting many tribes.

But many of the people seeking shelter inside sprawling U.N. compounds say the conflict is certainly ethnically based.

"We still don't feel secure, but it is definitely safer here," said Deng, a man who saw several dead bodies lying face down as he took his frightened family to a U.N. base in Juba.

In another development, the U.S. is moving additional Marines and aircraft from Spain to the Horn of Africa to provide embassy security and help with evacuations in South Sudan.

A defense official told The Associated Press that extra forces moving to Djibouti will bring the total U.S. troops in the region to 150, with 10 aircraft, including Osprey helicopters and C-130 transport planes.

Of those forces, about 45 U.S. Army troops are in South Sudan providing security. The remainder are in Djibouti, where the U.S. maintains its only permanent military base in Africa.

The official was not authorized to speak publicly so spoke on condition of anonymity.

Troops deployed last week helped evacuate Americans and other foreign nationals and provided security at the U.S. Embassy in Juba. Another couple hundred Americans remain in the country, the official said.

Three of the four U.S. troops injured Saturday when gunfire hit evacuation aircraft are stable and being sent to the military hospital in Germany, Warren said, while the fourth continues to get treatment in Nairobi, in neighboring Kenya. All were wounded in the lower body by small arms fire.

Al Jazeera and wire services