WASHINGTON: The United States will help south Sudan set up as an independent country if voters opt to secede in Sunday's referendum and is pleased by cooperation from Khartoum, once seen as spoiling for war over the oil-rich region, US officials said Wednesday. Assistant Secretary of State Johnnie Carson, the Obama administration's top diplomat for Africa, said Washington was encouraged the referendum starting on Jan. 9 would take place without a hitch, starting a process most analysts expect to result in south Sudan formally declaring independence in July. “We think that it will reflect the will of the people, that it will occur on time, peacefully and in a well-organized manner,” Carson told reporters. Carson said the United States stood ready to help south Sudan to achieve full independence, a tantalizing prospect for an impoverished and landlocked region that is one of Africa's budding oil producers. “The United States has invested a great deal of diplomacy to ensure that the outcome of this referendum is successful and peaceful,” Carson said, calling the weeklong vote for south Sudan the culmination of years of work following a 2005 peace deal that ended Africa's longest civil war. “We will also as a country help that new nation to succeed, get on its feet and to move forward successfully, economically and politically.” The United States has led pressure on the Khartoum government of President Omar Hassan Al-Bashir not to impede the secession vote. Carson said Washington was “extraordinarily pleased” by Bashir's statements on a trip to the south Sudan capital of Juba Tuesday that Khartoum was ready to let the south go. “We hope that the north ... will live up to those very promising statements,” Carson said. Bashir's visit is the latest sign that the referendum, which many analysts earlier said threatened to spark a return to war between the north and the south, may unfold peacefully. Key issues including borders, citizenship and the fate of the oil-rich region of Abyei remain to be decided, making the six-month transition period following the secession vote a potentially dangerous period. US officials are already working on a development plan for an independent south Sudan, which accounts for 70 percent of Sudan's overall oil production. The US is ready to recognize the new government quickly and appoint an ambassador to help lead efforts to improve basic infrastructure, healthcare, and education as well as trade and investment, officials said. “We anticipate ramping this up very quickly after the referendum,” said Larry Garber, the deputy administrator for Africa at the US Agency for International Development. A senior US official, speaking on background, denied suggestions the United States was motivated primarily by a interest in south Sudan's oil, which remains a key sticking point in dealings between Khartoum and Juba and which has been largely off limits to western oil companies thanks to US sanctions imposed on Sudan in 1997. North and south Sudan are now trying to work out how to share oil revenues after an independence vote, and the US official said Washington was confident the two sides would reach a political agreement. “We are fully confident that those arrangements can be made and a resolution can be made, on oil, on other economic issues, (and) on debt which is very important,” he said.