The return to combat by the Ethiopian government and the Tigray People's Liberation Front [TPLF] has alarmed the international community, which has been pushing both sides to peacefully resolve the brutal 21-month war in Africa's second most populous nation.
The situation on the ground was unclear a day after fresh fighting erupted on the border of Tigray, where the warring sides accused each other of igniting the first major clashes in five months.
On Thursday, Deputy Prime Minister and Foreign Minister Demeke Mekonnen told diplomats that Ethiopia was "prepared to defend the nation's territorial integrity and sovereignty".
"But it is equally committed to using peaceful means to put an end to the conflict and collaborating with humanitarian organizations to lessen needless suffering," he told a gathering of foreign envoys in Addis Ababa.
He also accused the TPLF of commandeering aid supplies meant for Tigray, which is in the grips of a major humanitarian crisis.
The UN's World Food Program on Thursday accused the TPLF of seizing half a million liters of fuel from a warehouse in Tigray, a region the rebels have held since ousting government troops in June 2021.
"We demand the Tigrayan Authorities return these fuel stocks to the humanitarian community immediately. As the next harvest is not until October, our deliveries of life-saving food could not be more urgent or critical to the survival of millions," WFP executive director David Beasley said in a statement.
Rebel authorities in Tigray said on Wednesday that government forces failed to breach their defensive lines, but offered little detail on the status of combat or casualties.
The government of Prime Minister Abiy Ahmed has also not provided an update on the fighting, or whether combat has spread beyond the scenes of Wednesday's battles on Tigray's southern border.
Spokespeople for Abiy's government and the rebel Tigray People's Liberation Front (TPLF) did not respond to AFP's requests for comment about the situation on the ground.
US Secretary of State Antony Blinken said the truce reached between the warring parties in March had "reduced violence and saved lives".
"We are concerned that renewed fighting puts that at risk. We call on the Ethiopian Government and TPLF to redouble efforts for peace to bring a permanent end to the conflict."
EU foreign policy chief Josep Borrell urged both sides to pull back from "a full blown war", saying: "Reports of renewed conflict in Northern Ethiopia cast a shadow on the prospect for peace."
UN chief Antonio Guterres and envoys from Britain, Turkey, the African Union and the East African trade bloc IGAD made similar calls for restraint and a commitment to dialogue.