The reported deployment of Eritrean forces into the Tigray region of northern Ethiopia, according to the European Union, will only help to intensify the conflict.
“The EU urges once again all parties to forget about any military solution and join efforts for the benefit of their populations,” said Josep Borrell, EU’s foreign affairs and security policy chief.
It comes amid a reported full-scale offensive by Eritrean troops along the Eritrea-Tigray border.
The Tigrayan forces spokesman, Getachew Reda, said the Eritreans were fighting alongside Ethiopian federal forces and regional militia.
But neither the Eritrean nor the Ethiopian governments have spoken about the reported entry of Eritrean forces.
An American envoy on Tuesday condemned the fighting, noting that the US was aware of Eritrean troops crossing into Tigray.
Eritrea has been allied with Ethiopian government soldiers in their almost two-year-long war against Tigrayan rebels.
Thousands of people have been killed and millions have been displaced in the conflict.