In a call with Ethopia’s deputy prime minister, Demeke Mekonnen, White House national security adviser Jake Sullivan expressed US concerns about the crisis in the Tigray zone, according to the White House.

During their phone call on Wednesday, the two “discussed crucial measures to resolve the crisis, including increased humanitarian access, cessation of hostilities, the evacuation of international forces, and credible inquiries into massacres and human rights violations,” according to the White House.

Ethnic rivalries over land, power and resources have ignited at several flashpoints before national elections scheduled for June in Ethiopia, Africa’s second most populous country.

Fighting in the northern Tigray region has killed thousands of people and forced hundreds of thousands from their homes amid shortages of food, water and medicine. Ethiopian Prime Minister Abiy Ahmed has said Eritrea agreed to withdraw troops it had sent into Ethiopian territory along their mutual border. Eritrea has denied its forces joined the conflict.

The US State Department announced on Monday that it is investigating allegations of human rights violations and massacres in Tigray.

Sullivan and Mekonnen have addressed the value of continuing regional dialogue to settle conflicts over the Grand Ethiopia Renaissance Dam, a massive Blue Nile hydroelectric project that has alarmed Sudan and Egypt, according to the White House.