Ethiopia-Eritrea Border Tensions: Troops Mass as U.S. Warns of a Wider War

Tension along the Ethiopia-Eritrea border is drawing new U.S. attention. Secretary of State Marco Rubio said on Saturday, Oct. 17, 2026, that troops were “surging on both sides” of the frontier and warned that the buildup could become a wider war. His remarks came about four weeks after fighting resumed in Ethiopia’s Tigray region and less than two weeks after Eritrean troops were reported inside Tigray.

Rubio spoke to reporters at Joint Base Andrews before leaving for Uzbekistan and India. “Anytime you see troops on both sides of the border in a place like that, you’re always worried that that can turn into a broader conflict,” he said, according to the State Department transcript as reported by HahuPrime. He urged Ethiopia to be “wise and measured” in its response so the crisis “doesn’t turn into a broader war which could ultimately pull in other countries.”

How the Ethiopia-Eritrea border crisis began

Fighting broke out on Sept. 23 between Ethiopian federal forces and the Tigray People’s Liberation Front (TPLF), the party that controls Tigray, AFP reported. Both sides blame each other for violating the 2022 deal that ended a two-year civil war. Ethiopia accuses Eritrea of backing the TPLF, which Eritrea denies. The two neighbors cut diplomatic ties at the start of October, as covered in Ethiopia and Eritrea cut ties.

Key dates since then:

• Oct. 3–4: The Ethiopian army entered the Tigray capital, Mekelle, without a fight after the TPLF withdrew, according to AFP. Earlier coverage: Tigray capital Mekelle retaken.
• Oct. 7: The conflict monitor ACLED said Eritrean troops crossed the border at Zalambessa. Witnesses told AFP that soldiers with heavy weapons were in Adigrat, about 25 miles south of the border.
• Oct. 7–8: Ethiopian government drones struck Eritrean forces in Adigrat, ACLED said, according to The Guardian.
• Oct. 8–9: In a letter to the U.N. Security Council, Foreign Minister Gedion Timothewos accused Eritrea of an “all-out invasion” and said its forces had advanced up to 60 kilometers (37 miles) into Tigray, the BBC reported. See also Ethiopia’s U.N. self-defense letter.
• Oct. 15: Ethiopian forces and the allied Tigray Peace Force entered the historic city of Aksum, and ACLED reported Eritrean troops withdrawing through Zalambessa, Al Jazeera reported.

What each side says

Ethiopia says it is acting in self-defense. “In this time of difficulty, when Ethiopia is left with no other option but to defend itself, we count on your understanding, support, and solidarity,” its letter to the Security Council said, according to the BBC.

Eritrea rejects that account. Information Minister Yemane Gebremeskel said his country faces “an unprovoked war of aggression.” On X, he accused Ethiopia of “openly working to bring about regime change in Eritrea” by sheltering armed opposition groups, the BBC reported. He also rejected claims by the Tigray Peace Force that Eritrean forces had suffered heavy losses, telling local media they were false, according to Al Jazeera. Neither side’s claims about troop positions or casualties have been independently verified.

AFP reported that Eritrea fears landlocked Ethiopia plans to seize direct access to the Red Sea, and that analysts say Asmara wants to keep the fighting from reaching its own territory. The BBC reported that relations had already deteriorated over Prime Minister Abiy Ahmed’s stated ambition to gain ownership of an Eritrean port.

U.S. sanctions and diplomacy

Rubio was asked whether the U.S. made a mistake by lifting Ethiopia-related sanctions shortly before the violence. “No, I don’t think the sanctions lifting – these were very small sanctions, and they don’t really have anything to do with what’s happening over there,” he said. Those measures, imposed in 2021 over Eritrea’s role in the Tigray war, lapsed on Sept. 18. The Treasury Department then removed the Eritrean Defense Forces and the ruling People’s Front for Democracy and Justice from its sanctions list, HahuPrime reported, citing Treasury records.

Rubio said the move opened contact with Asmara. “It’s hard to serve the role of mediator and peacemaker unless you can talk to both sides,” he said. According to the State Department’s readout of an Oct. 14 call, Rubio told Abiy that all Horn of Africa countries “must respect the sovereignty and territorial integrity of their neighbors and avoid cross-border incursions.” The readout also said the only sustainable solution was dialogue under the 2018 Ethiopia-Eritrea peace framework, HahuPrime reported. AddisMizan reported that Rubio also acknowledged the security challenges Ethiopia faces while calling for restraint.

What to watch

The two countries fought a border war from 1998 to 2000 that killed tens of thousands. Signs of where the crisis is heading include troop positions around Zalambessa and further Security Council action. A third is whether Washington’s stated plan to talk with both capitals produces direct talks. Fighting in northern Ethiopia also borders on other Horn of Africa crises, including Sudan’s war, covered in a Sudan drone strike near the Ethiopian border.

Featured photo: A street in Adigrat, Tigray, Ethiopia, by Rod Waddington, CC BY-SA 2.0, via Wikimedia Commons (cropped; license). File photo.

Sources

• BBC: Ethiopia warns Eritrea it will defend itself after troops cross border
• AFP: Eritrean troops deploy in Ethiopia’s Tigray region
• The Guardian: Ethiopia launches drone attack against Eritrean troops who crossed into Tigray
• Al Jazeera: Ethiopian forces expand control in Tigray as militia claims Eritrean losses
• AP News: Ethiopia accuses Eritrea of troop incursion in UN self-defense letter
• HahuPrime: Rubio warns Ethiopia-Eritrea border buildup risks wider war
• AddisMizan: Rubio urges measured Ethiopian response, warns of wider war