The US has called for the immediate withdrawal of Eritrean troops in Ethiopia’s Tigray region.
“Credible reports” had emerged of their involvement in human rights abuses, including sexual violence and looting, the state department said.
This is its first statement on the conflict since the Joe Biden administration took office last week.
Both the Eritrean and Ethiopian governments deny that Eritrean forces are in Tigray, which borders Eritrea.
Eritrea is a highly militarised one-party state ruled by President Isaias Afwerki since 1993.
Thousands of people have been killed and about two million people, or one-third of Tigray’s population, have fled their homes since conflict broke out in early November.
Dialogue between the Ethiopian government and Tigrayans was “essential”, and humanitarian aid needed to be “mobilised” immediately because of “credible reports” that hundreds of thousands of people may starve to death, the US state department said.
Eritrea appeared to have launched artillery attacks from its side of the border, and had troops in Tigray, though the exact number was unclear, it said.
“The United States has made clear its position that all Eritrean troops need to leave Tigray immediately, given credible reports of looting, sexual violence, assaults in refugee camps and other human rights abuses.
“There is also evidence of Eritrean soldiers forcibly returning Eritrean refugees from Tigray to Eritrea,” it added in a statement.
Nearly 100,000 Eritreans had lived in four camps in Tigray after fleeing political persecution and military conscription over the last decade.
Ethiopian Prime Minister Abiy Ahmed won the Nobel Peace Prize in 2019 for restoring relations with Mr Isaias’ government, almost two decades after the two nations fought a border in Tigray that left up to 100,000 people dead.
Last month, Mr Abiy admitted that Eritrea had hosted armed Ethiopian troops who had retreated to its territory after the Tigray Peoples Liberation Forces(TPLF) captured their bases in Tigray in early November.
However, he did not acknowledge that Eritrean troops had entered Tigray to bolster the fight against the TPLF.
The TPLF had been the ruling party in Tigray for almost three decades.
It said it had seized the military bases in a “pre-emptive strike” following a breakdown in relations with Mr Abiy’s government. -BBC