The state-run Ethiopian Broadcasting Corporation quoted Abiy saying the rebels had sustained “heavy losses and (were) unable to cope with the strike by allied forces”.
“The enemy will be hit, and the victory will continue,” he said.
Abiy – who won the Nobel Peace Prize two years ago – announced last month he would head to the battlefront following a series of advances claimed by the rebels, as fighting reportedly raged on at least three fronts.
And over several days last week, the government said the military and its allies had retaken the UNESCO World Heritage site of Lalibela, which had fallen to TPLF fighters in August and the town of Shewa Robit which lies only 220 kilometres from Addis Ababa by road.
TPLF spokesperson Getachew Reda said on Twitter late Monday that rebel forces had left towns including Kombolcha and Dessie “as part of our plan”.
On Sunday, TPLF leader Debretsion Gebremichael had denied the government was scoring major victories, saying the rebels were making strategic territorial adjustments and remained undefeated.
“The enemy is getting stronger, so we also have to be strong and intensify our struggle,” he said.