BEIJING/KHARTOUM – Sudan's war crime-indicted president will seek to soothe his most powerful ally's worries about its investments when he visits China next week, days before Sudan's oil-rich south splits from the north. That July 9 secession is the outcome of a January referendum that will see President Omar Hassan al-Bashir and his government in the northern capital Khartoum lose three-quarters of the country's current oil output, roughly 500,000 barrels per day. Sudan is one of China's largest foreign supplier of crude oil, making Beijing all the more keen to ensure a smooth transition along the volatile north-south border and that supplies are not interrupted. "Everyone knows the elephant in the room is China's investment in Sudan. The security of its interests is a big concern for China," said He Wenping, an Africa expert at top government think tank the Chinese Academy of Social Sciences. Khartoum seized the main town in the north-south border region of Abyei on May 21, raising fears the two sides could return to conflict. But Sudan's military and the south's Sudan People's Liberation Army agreed this week to withdraw forces in favor of Ethiopian peacekeepers. China has made a general policy of not getting involved in other countries' domestic affairs, but with the security of its oil imports on the line, China says it has already been a force for stability in Sudan. China's special envoy for Africa Affairs and former envoy to Sudan's conflict-torn Darfur region, Liu Guijin, told reporters on Thursday that China had "done a lot of work to persuade" the north to implement the peace agreement and referendum. Issues concerning Sudan's security would certainly be on the agenda during Bashir's trip, which begins on Monday, he added. "But no matter how strong the outside pressure, no one can replace the Sudanese parties in making a decision," Liu said. Fouad Hikmat, a Sudan analyst with the International Crisis Group, said Khartoum was eager to ensure that its relations with China were solid after the split and would likely seek to reassure Beijing that its investments were safe. "He's going to have to go and tell China that these investments are not going to be thrown out. They need to maintain friends at the international level, and therefore China is extremely important," Hikmat said. The north and south have yet to come to terms on how to manage the oil industry after the split, but China has been increasingly engaging with leaders from south Sudan, where it has opened a consulate and jumped into several projects. Much of the oil comes from the south, but most of the refineries, pipelines and ports are in the north. "China has a half a dozen projects in the south of Sudan, and as it is fully capable of playing on both sides of the street," said Barry Sautman, a professor at Hong Kong University of Science & Technology and an expert on China's role in Africa.