The United States established diplomatic relations with Sudan in 1956, following its independence from joint administration by Egypt and the United Kingdom. Sudan broke diplomatic relations with the United States in 1967 after the start of the Arab-Israeli War. Relations were reestablished in 1972. In the 1990s, The Sudanese Government’s links with international terrorist organizations led the United States to designate Sudan in 1993 as a state sponsor of terrorism and to suspend U.S. Embassy operations in 1996. The U.S. Embassy was reopened in 2002. Sudan has provided concrete cooperation against international terrorism since the September 11, 2001 terrorist strikes against the United States. The United States helped create the 2005 Comprehensive Peace Agreement that laid the groundwork for South Sudan's 2011 independence referendum and secession. Several disputes between Sudan and South Sudan remain unresolved, including the management of oil resources and the status of the Abyei region. The United States supports the efforts of the African Union High-Level Implementation Panel to help the two countries resolve these disputes. U.S. policy on Sudan aims to achieve an end to conflict and gross human rights abuses and to ensure that Sudan does not harbor international terrorists.