Eritrea has reopened its embassy in Ethiopia in further evidence of a rapid thaw between the two countries that a week ago ended two decades of military stalemate over a border war in which tens of thousands died.

In a brief ceremony on Monday, Ethiopia’s Prime Minister Abiy Ahmed and Eritrea’s President Isaias Afwerki jointly raised the Eritrean flag inside a newly refurbished embassy as a military band played Eritrea’s anthem.

Ethiopia and Eritrea expelled each others’ envoys at the start of a 1998-2000 border war that killed around 80,000 people.

Monday’s embassy visit marked the end of the Eritrean leader’s three-day stay in Ethiopia, which also included a visit to an industrial park and a Sunday evening dinner and concert attended by thousands of Ethiopians.

Abandoned cars of last Eritrean Ambassador to Ethiopia are seen during a inauguration ceremony marking the reopening of the Eritrean embassy in Addis Ababa [Tiksa Negeri/Reuters]

Al Jazeera’s Mohamed Adow, reporting from Addis Ababa, said on Monday that both countries stand a chance to benefit economically from the new reality.

“Ethiopia was declared landlocked [due to the state of war]. It had no way of using the ports of Asaba and Massawa in Eritrea. Now, Ethiopia is looking forward to regaining access to them. And Eritrea is excited at that possibility,” he said.

Rapid thaw in relations

The visit came just a week after Abiy signed an agreement with Afwerki during a landmark trip to Eritrea’s capital Asmara. The agreement formally declared that the “state of war” between the neighbouring countries was over.

Abiy said last Tuesday that his government wanted to implement a deal restoring relations with Eritrea quickly to “make up for lost opportunities” after a two-decade military standoff.

Isaias arrived in Ethiopia for a three-day trip on Saturday [Minasse Wondimu Hailu/Anadolu]

Eritrea and Ethiopia have so far agreed to open embassies, develop ports and restart flights.

Ethiopian Airlines is scheduled to conduct the first passenger flight between Ethiopia and Eritrea on Wednesday.

The newly appointed reformist Abiy first instigated the peace overtures and restoration of relations in April.

The Horn of Africa nations had remained at loggerheads since Ethiopia rejected a United Nations ruling and refused to cede to Eritrea land along the countries’ border following a 1998-2000 war.