Ethiopian Prime Minister Abiy Ahmed vowed on Tuesday "to implement honestly" a ceasefire agreement between his government and forces in Tigray, which he said was necessary to ensure peace proved sustainable.

The truce signed November 2 agreed to end two years of war that has devastated the Tigray region, killing thousands, displacing millions and threatening the unity of Africa's second-most populous nation.

Abiy's government and representatives from Tigray on Saturday signed a further deal for implementing the ceasefire.

"We have moved one step forward. We have discussed, agreed and signed. The next thing expected from us will be to implement honestly what we have promised to make the peace sustainable," Abiy told Ethiopia's national parliament after hearing questions from lawmakers.

The comments were his first on the truce since he issued a statement on November 2.