In a statement, the US State Department expressed deep sadness over the killing of three MSF staff members in the Ethiopian region of Tigray, and stressed the need for an end to attacks on humanitarian workers there.
The statement called for an independent investigation and for the perpetrators to be held accountable for the killings.
The US State Department held the Ethiopian government fully responsible for ensuring the safety of humanitarian workers and the access of aid.
For its part, the European Union condemned the killing of "Doctors Without Borders" staff in the region, and renewed the call for an immediate ceasefire.
Three Médecins Sans Frontières workers, two Spanish and two Ethiopians, were killed in an attack in Tigray province.
"We lost contact with them and the car in which they were traveling yesterday afternoon, and this morning the car was found empty and their bodies a few meters away from it," the Spanish branch of Doctors Without Borders said in a statement. brutal".
The Ethiopian Foreign Ministry said on Twitter Friday that the three aid workers were killed in the town of Abi Adde, 50 km west of Mekele, the regional capital.
"The Tigray People's Liberation Front is actively operating" in this area, she added.
The region witnessed a military escalation in recent days, and an air raid targeted a market there, killing at least 64 people.