The government of Ethiopia says a referendum will be held to resolve the territorial dispute between the northern Amhara and Tigray regions.
The dispute poses a risk to the delicate calm that has prevailed in Tigray since the end of the civil war a year ago.
Before Amhara forces took control of the fertile lands in 2020 during the conflict, Tigray was in control of them.
Rights groups have accused those forces of carrying out ethnic cleansing in the disputed areas.
The allegations were dismissed by Amhara’s regional government.
The disputed areas, near Ethiopia’s border with Sudan, were a key flashpoint in the two-year conflict between the Tigray People’s Liberation Front (TPLF) and the federal government.
The war ended after a peace agreement was signed last November in South Africa.
Many of the one million displaced people, who remain sheltered in makeshift camps throughout Tigray, are reported to have fled the contested areas.
The Amhara administration says the territory was forcibly annexed by Tigray in the 1990s when the TPLF was the dominant political force in Ethiopia.
In a report last year, rights groups Amnesty International and Human Rights Watch said evidence collected through interviews showed that the disputed areas had been the site of some of the worst atrocities committed during the conflict and were been largely ignored.
The African Union envoy, former Nigerian President Olusegun Obasanjo, has said around 600,000 people died during the conflict overall. Researchers put the hundreds of thousands of civilian deaths down to fighting, starvation and lack of health care.
The federal authorities say they have “taken a position on the fate of the disputed areas to find a solution mutually beneficial to all sides”.