South Africa and Namibia held talks aimed at resolving a long-running disagreement over rights to the Orange river, a key water source that demarcates the border between the two nations, and were confident the matter could be resolved amicably.

A treaty signed in 1890, when the neighbors were under colonial rule, specifies that the border runs along the northern bank of the river — which would place it under South Africa’s jurisdiction. While Pretoria continued to recognize that demarcation, Namibia wants the the borderline moved to the middle of the river. Water is scare in both countries, a problem exacerbated by climate change.

Following two days of negotiations between South African and Namibian foreign-affairs officials, they issued a joint statement in which they signaled their “commitment to work in a collaborative manner, guided by principles of good neighborliness, transparency and mutual trust, for the conclusion of the negotiations on the Orange river boundary.”

They will refer a report drafted by experts from both sides to their respective presidents for further consideration, they said.

Namibia has also previously expressed concern about South Africa’s plans to tap additional water from Lesotho on the grounds that it may have an adverse effect on flows in the Orange river. The country has wrangled with Botswana over rights to two islands situated in the Chobe river, with the International Court of Justice ruling in Botswana’s favor.

Positioned between the Namib and Kalahari deserts, Namibia has sub-Saharan Africa’s most arid climate and has unpredictable rainfall and high evaporation rates, resulting in a water deficit that’s intermittently compounded by drought. Calle Schlettwein, the nation’s water affairs minister, told a conference in Cairo on Tuesday that the country needed to invest $1.4-billion over the next decade to safeguard its water security.

The commitment shown by South Africa and Namibia to resolve their differences cordially contrasts with an acrimonious dispute over Ethiopia’s construction of a mega dam on the Nile River, with neighboring Ethiopia and Sudan expressing fears about disruption to their water supply.