The United States special envoy for the Horn of Africa is due in the Ethiopian capital, for talks as the country’s civil war continues to escalate.

Jeffrey Feltman is to meet government representatives a year after Tigrayan insurgents seized federal army bases, sparking a conflict that has since claimed thousands of lives.

The US state department says it’s troubled by the expansion of combat operations in Ethiopia.

Tigrayan rebel forces claim to have taken another town, Kemise, along a major highway 330 kilometres (200 miles) north of Addis Ababa.

In a defiant speech to mark the first anniversary of the war, Prime Minister Abiy Ahmed said his enemies would be buried with the blood and bones of his forces.

Ethiopia’s international partners are sounding the alarm over the escalating violence in the country which now threatens the capital.

The US says it’s doubling down on diplomatic efforts to get the government and the rebel forces to talk.

The United Nations’ Secretary General Antonio Guterres says he spoke to Mr Abiy on Wednesday to offer mediation support.

But both sides in this conflict have dismissed negotiations.