0540 GMT January 16, 2021
The nearly month-long war has killed hundreds and probably thousands, sent refugees into Sudan, enmeshed Eritrea, affected a peacekeeping mission in Somalia, and deepened divisions between Ethiopia's myriad ethnic groups, Reuters wrote.
Abiy's troops took Tigray's capital Mekelle at the weekend and declared defeat for the Tigray People's Liberation Front (TPLF), a guerrilla movement-turned-political party that dominated national government for nearly three decades until 2018.
"Our constitution was attacked but it didn't take us three years, it took us three weeks," Abiy told Parliament, comparing his offensive with the American Civil War of the 1860s.
"Our army is disciplined and victorious," he added, saying federal troops had not killed any civilians nor damaged Mekelle after launching a Nov. 4 offensive in response to a TPLF attack on an army base.
Drones were used to watch the TPLF, but federal forces declined to fire rockets in Tigray, Abiy said. "Even though we have better capacity, we won't use it. We are not the junta ... We conduct ourselves responsibly."
Though the highland city of 500,000 people fell with little resistance, the TPLF later said it had shot down a plane, retaken one town, and was resisting.
TPLF leader Debretsion Gebremichael, a 57-year-old former radio operator, denied reports that he had fled to South Sudan and said his forces had captured some soldiers from neighboring Eritrea around Wukro, about 50km (30 miles) north of Mekelle.
"I'm close to Mekelle in Tigray fighting the invaders," Debretsion Gebremichael said.
The TPLF has shelled Asmara airport and accused Eritrea of sending troops over the border to fight with Abiy's forces, but Eritrea's foreign minister denied any role in a Nov. 10 interview.
When he took office in 2018, Abiy pledged to unite Ethiopia's 115 million people, but there have been repeated bouts of ethnic bloodshed and hundreds of thousands have had to flee their homes due to those clashes.
In Tigray, both sides have spoken of hundreds of dead in the Tigray war, and diplomats believe the toll is in the thousands. Tens of thousands more have been uprooted from their homes.