"We have just formed an alliance. We are cooperating with several groups and our goal is to overthrow the regime and enable a transitional government," Amanuel Assefa, vice chairman of the separatist TPLF, told AFP.
A flare-up of fighting in northern Ethiopia over the past year has raised concerns that the peace agreement will collapse and war will break out again in the country.
During the civil war between the government army and the Tigray People's Liberation Front from 2020 to 2022, around 600,000 people were killed.
Ethiopia's central government is led by Nobel Peace Prize-winning Prime Minister Abiy Ahmed.
