Two US Senators have sent a letter to the State Department requesting for help over the detention of Ethiopian opposition figure Jawar Mohammed.
Senators Amy Klobuchar and Tina Smith want the department to “take all appropriate actions” to ensure that Mr Jawar and fellow activist Misha Chiri “are treated humanely”.
They also want the department to assist the pair to “exercise their full rights”.
Mr Jawar was previously exiled in the US where he established a media business in Minnesota.
He was detained last month by Ethiopian authorities after being linked to the murder of a policeman during violent protests following the killing of music star Hachalu Handessa in the capital, Addis Ababa.
Mr Jawar’s allies deny his involvement in the murder.
“The recent political unrest and responsive actions taken by the Ethiopian government have threatened the progress that has been made,” the senators said in their letter.