The Luao River forms part of the boundary between Angola and the Democratic Republic of the Congo.

However, it was discovered that Lago Dilolo drained southeast into the Zambezi watershed rather than north to the Kasai.

Eventually Belgium ceded a large area west of the Luau River in an exchange of territories agreed on 22 July 1927.

[2] In return for the "Dilolo Hook", Belgium gained a smaller area to the northwest which opened an easier railway route from Matadi to Léopoldville.

[1][better source needed] The Benguela railway, built by a subsidiary of Tanganyika Concessions, was completed from Lobito on the Atlantic coast to Dilolo in August 1928.