WASHINGTON: The United States called Wednesday on Ethiopia and Eritrea to pursue “de-escalation” amid fears of war between the Horn of Africa neighbors.

US Secretary of State Marco Rubio stressed in a phone call with Ethiopian Prime Minister Abiy Ahmed that “all countries in the Horn of Africa must respect the sovereignty and territorial integrity of their neighbors and avoid cross-border incursions,” according to a statement from his office.

Eritrea, a former Ethiopian province that gained independence in 1993, has deeply strained relations with Ethiopia. The two neighbors accuse each other of attempting to destabilize their countries. They fought a war over territorial disputes from 1998 to 2000 that killed tens of thousands of people.

“The Secretary supports de-escalation by all sides,” the State Department said. “The only sustainable solution to internal and external tensions is achieved through dialogue and engagement as agreed to in the 2018 Ethiopia-Eritrea peace framework.”

Ethiopian federal forces and their allies are closing in on a town near the Eritrean border, a commander of a pro-government militia and a resident said Wednesday.

Thousands of Eritrean soldiers were deployed last week, according to a security source, to Tigray, Ethiopia’s rebellious northern region, which had until then been governed by the Tigray People’s Liberation Front (TPLF). The group took up arms again last month against Ethiopian federal forces in the north of the country.

Rubio stressed “that the region cannot tolerate more conflict,” the State Department said.