Ethiopia announced Tuesday that it would accept a 2000 peace agreement with Eritrea over their disputed border, potentially a major step toward resolving one of post-colonial Africa’s bloodiest and most protracted conflicts.

A statement by the governing party of Ethiopia, the second-most populous country in Africa, said it would “fully accept and implement” the agreement with Eritrea, a former province of Ethiopia, which was signed but never honored.

“The Eritrean government should take the same stand without any prerequisite and accept our call to bring back the long-lost peace of the two brother nations as it was before,” the governing party, the Ethiopian People’s Revolutionary Democratic Front, said in the statement.

The countries fought a war from 1998 to 2000 over their border dispute, which left about 80,000 people dead. They signed a peace agreement in 2000, but the Ethiopians never accepted the findings of a boundary commission established by the agreement.