According to a State Department official, US Secretary of State Antony Blinken is deeply worried by Ethiopia’s military escalation and has urged for immediate talks to resolve the problem.

The remarks came only hours after Ethiopian Prime Minister Abiy Ahmed joined the national army on the front lines.

“Secretary Blinken voiced severe concern about disturbing indicators of military escalation in Ethiopia and urged the urgent need to go to discussions,” Ned Price said late Friday.

Price made the announcement following a phone chat between Kenyan President Uhuru Kenyatta and Blinken.

On Friday, Ethiopia’s state-affiliated Fana Broadcasting reported that Abiy was on the frontline with the army fighting rebellious Tigrayan forces in the northeastern Afar region. Abiy posted the same video on his Twitter account.

Abiy’s government has been fighting Tigrayan forces for more than a year, in a conflict that has killed thousands and displaced millions in Africa’s second-most populous nation.