Based on the colonial borders established by the British and German governments, the modern-day boundary between Namibia and South Africa follows the Orange River from the South Atlantic Ocean inland to the 20th degree of longitude which it then follows northward to the tripoint with Botswana. The Orange River section of the boundary, which runs for just over 600 kilometers (373 miles), is disputed by the two States. Namibia claims a median line boundary for the river, while South Africa claims the northern bank. The straight line section of the frontier, which extends for just over 400 kilometers (250 miles), was demarcated by the colonial powers. Despite the dispute and a history of strained relations, diplomatic ties between the two countries have improved in recent years.