While U.S. officials are making a diplomatic push to keep the south Sudan independence referendum on schedule for January, analysts say China, a major ally of Sudan's government, also has an important role to play. The U.S., China rivalry is being played out over Sudan's uncertain future.
The U.S. Congress is introducing new legislation to encourage Sudan to keep its previous peace engagements in exchange for normalizing ties, while Sunday, Sudan's President Omar al-Bashir praised China for how it cooperates with African countries.
The new U.S. bill, which has bipartisan support, is projected to be passed into law before the end of the year. It comes as the U.S. diplomatic presence is steadily growing in south Sudan.
China, meanwhile, is making sure it maintains its extremely favorable ties with the government in Khartoum, while deepening its own links in the south.
China has been buying huge amounts of oil from Sudan's landlocked south which run through northern pipelines, linking China to both parts of the country.
In recent years, China has also supplied the government in Khartoum with large amounts of military equipment and diplomatic support. Chinese officials have said they are in favor of a united Sudan, but will respect the outcome of the referendum if southerners choose independence.
American scholar Eric Reeves, a Sudan researcher at Smith College, initiated a campaign branding the 2008 Olympic Games in Beijing the "genocide Olympics" because of the ongoing war in Sudan's western Darfur province and China's links to the conflict.
Reeves says even though the United States and China may want peace for southern Sudan, officials in Khartoum may have other plans. "I think it is an ideal opportunity for the United States and China to work together. Khartoum has enjoyed diplomatic protection from Beijing for far too long at the Security Council. Some of that changed with the "genocide Olympics" campaign I started because it was in their self-interest not to have their Olympics, their international coming out party tagged as the "genocide Olympics", but there was never really a threat to China's economic interests by virtue of their enabling Khartoum. Now, there is. If I had to bet, Khartoum will either abort, abrogate or militarily subvert the results of the self-determination referendum if it is allowed to take place at all," he said.
A former U.S. ambassador in Africa, David Shinn, says China pressured Khartoum to accept international peacekeepers in Darfur, in part because of issues related to the Olympics. He says China's role is also crucial in terms of the referendum.
Shinn, who is currently researching China's growing role in Africa, says Chinese officials are paying more and more attention to officials from the former southern rebel Sudan People's Liberation Movement, known as the SPLM.
This includes inviting them to Beijing, as well as opening a consulate in the former rebel headquarters of Juba, the capital in southern Sudan. "They are going to great lengths to try to ensure that they are well situated in the south on the assumption the south votes for independence," Shinn said.
Shinn says Chinese officials follow a consistent approach of establishing economic ties in areas of interest, such as those containing vast amounts of oil like in southern Sudan, with whoever the authorities are.
"They will simply try to do business, whatever it takes to get it done. And if the SPLM is on the same page, they may very well succeed. So I think that will be the focus of the Chinese effort to shore up their relations with the southern government assuming it becomes independent, and operate on a business-like basis," he said.
But Kevin Funk, an independent writer, and co-author of a book called "The Scramble for Africa: Darfur Intervention and the USA" sees the situation in Sudan as an example of China-US rivalry over resources and military ties on the continent.
Funk points to reports that U.S. allies in east Africa are sending weapons to southern Sudan. "There have been reports that both Ethiopia and Kenya have been providing the SPLM with weapons. The fact they are strong U.S. allies and given the broader contours of U.S. policy suggests the U.S. role in south Sudan is not as disinterested as it might commonly be portrayed," he said.
Other analysts, like John Prendergast from the U.S.-based Enough Project to end genocide, see the situation with more optimism. He says southern Sudan's scheduled referendum is an opportunity for the world's two biggest economies to cooperate in the interests of peace in Africa.
"Both countries, China and the United States, have an interest in peace. They may have different motivations, the Chinese have a bigger interest, national security interest, in Sudan because they want unimpeded access to that oil. They have sunk $10 billion into the oil sector, they would be fools to want to have war erupt again and not react to that. So it seems to me this is a great opportunity for the United States to work with China to prevent war in the south to secure China's economic interests and secure America's humanitarian interests in conflict prevention in Sudan," he said.
The referendum would be the culmination of the Comprehensive Peace Agreement which was signed in 2005 between the Sudan People's Liberation Movement and the government of Sudan to end two decades of conflict which killed an estimated two million people. Other obstacles include logistics, establishing proper voting lists, border demarcation and how oil profits will be shared if the south votes for independence.