Jeffrey Feltman, special envoy for the Horn of Africa, will hold talks on Thursday and Friday to urge "all Ethiopians to commit to peace and resolution of grievances through dialogue," a State Department spokesperson said.

Earlier today, Feltman, said Washington had directly warned TPLF leaders not to advance on the capital and instead to pursue talks.

He voiced exasperation at allegations in Addis Ababa that the United States is seeking to overthrow Abiy and install a government along the lines of late strongman Meles Zenawi, a former TPLF chairman.

"That is just not true," Feltman said.

Late on Tuesday, the Ethiopian authorities ordered residents of the capital to register their firearms as state-affiliated media announced a nationwide state of emergency and ordered residents of Addis Ababa to prepare to defend their neighbourhoods.