An Eritrean delegation is due to arrive in the Ethiopian capital on Tuesday, a government official said, in an historic diplomatic move aimed at ending decades of hostility.
"The Eritrean delegation is arriving not only today, but in a few hours," said foreign ministry spokesman Meles Alem.
The sudden thaw in relations between the bitter foes follows an unexpected olive branch offered by new Ethiopian Prime Minister Abiy Ahmed.
Earlier this month Abiy said he would abide by a 2002 border ruling and withdraw from contested territory between the two countries.
Eritrea's President Isaias Afwerki responded last week saying he would dispatch a delegation, "to gauge current developments directly and in depth as well as to chart out a plan for continuous future action."
A former province, Eritrea voted for independence from its much larger southern neighbour in 1993, but the two countries fought a border war between 1998-2000 that killed around 80,000.
Since then, both have maintained a cold war footing with shots occasionally fired, and backed each other's rebels.
The apparent detente has raised hopes of a normalisation of relations that might boost regional trade and ease tensions.
On Tuesday twinned Eritrean and Ethiopian flags lined the main road to the airport where a red carpet was laid out and a brass band assembled.
Abiy is expected to greet the Eritreans in person when they land later in the day.
Abiy said he would abide by a 2002 border ruling and withdraw from contested territory between the two countries