Ethiopia's Prime Minister Abiy Ahmed has gone to direct the war effort from the front lines, state-affiliated media reported on Wednesday, and Deputy Prime Minister Demeke Mekonnen Hassen will take charge of routine government business in his absence.

Government spokesperson Legesse Tulu detailed the transfer of some routine duties in a news conference, the report from Fana news outlet said.

Abiy announced late on Monday he was planning to personally direct the fight against Tigrayan forces and their allies.

"Let's meet at the war front," he wrote "The time has come to lead the country with sacrifice."

Last month Tigrayan forces and their allies threatened to march on the capital Addis Ababa; they have also been fighting fiercely to try to cut a transport corridor linking landlocked Ethiopia with the region's main port Djibouti.

On Tuesday, US Special Envoy Jeffrey Feltman said the Ethiopian military and regional militias had been able to hold back Tigrayan attempts to cut the corridor but Tigrayan forces had been able to move south towards Addis.

Ethiopia's military spokesperson did not respond to requests for comment.