Sudan's administrative boundary with Kenya does not coincide with international boundary, and Egypt asserts its claim to the "Hala'ib Triangle", a barren area of 20,580 sq km under partial Sudanese administration that is defined by an administrative boundary which supersedes the treaty boundary of 1899.

Solidarity with other Arab countries has been a feature of Sudan’s foreign policy. When the Arab-Israeli war began in June 1967, Sudan declared war on Israel. However, in the early 1970s, Sudan gradually shifted its stance and was supportive of the Camp David Accords.

Relations between Sudan and Libya deteriorated in the early 1970s and reached a low in October 1981, when Libya began a policy of crossborder raids into western Sudan. After the 1985 coup, the military government resumed diplomatic relations with Libya, as part of a policy of improving relations with neighboring and Arab states. In early 1990, Libya and the Sudan announced that they would seek “unity.” This unity was never implemented.

During the 1990s, Sudan sought to steer a nonaligned course, courting Western aid and seeking rapprochement with Arab states, while maintaining cooperative ties with Libya, Syria, North Korea, Iran, and Iraq. Sudan’s support for regional insurgencies such as Egyptian Islamic Jihad, Eritrian Islamic Jihad, Ethiopian Islamic Jihad, Palestinian Islamic Jihad, Hamas, Hizbullah, and the Lord’s Resistance Army generated great concern about their contribution to regional instability. Allegations of the government’s complicity in the assassination attempt against the Egyptian president in Ethiopia in 1995 led to UN Security Council sanctions against the Sudan. By the late 1990s, Sudan experienced strained or broken diplomatic relations with most of its nine neighboring countries. However, since 2000, Sudan has actively sought regional rapprochement that has rehabilitated most of these regional relations.