US Secretary of State Antony Blinken said on Wednesday that there was “no military resolution to the differences that exist” among warring parties in Ethiopia.
Mr Blinken said Washington was in close contact with the African Union envoy trying to help the different sides to reach a political settlement.
Ethiopia reportedly rounded up high-profile members of the Tigrayan ethnic group and 16 UN staff members and their dependents.
The UN personnel were reportedly detained under an emergency decree that Prime Minister Abiy Ahmed issued last week after fighters from the Tigray People’s Liberation Front made further advances towards the capital, Addis Ababa.
“All sides see the dangers of perpetuating the conflict and there is an opportunity, I hope, for everyone to pull back, to sit down, to get a halt to what’s happening on the ground and ultimately to produce a ceasefire, to have access for humanitarian assistance and, over time, to negotiate a more durable political resolution,” Mr Blinken said at the State Department.
“I do think there’s an opportunity born out of necessity because the alternative to conflict that overtakes Ethiopia [and] spills out of the country into the region should be sobering to everyone and to all concerned.
"There is still a window to pull back and to move this to a better place."
Former Nigerian president Olusegun Obasanjo is trying to broker a ceasefire between Mr Abiy and the TPLF on behalf of the African Union, alongside Jeffrey Feltman, the US special envoy for the Horn of Africa.
Mr Blinken spoke with Mr Obasanjo and Ethiopian Foreign Minister Demeke Mekonnen by phone on Wednesday.
“The secretary and President Obasanjo discussed the urgent need for a halt to all military operations, negotiations on a cessation of hostilities without preconditions and unhindered humanitarian access,” State Department spokesman Ned Price said.
“The secretary expressed his concern that the bellicose rhetoric on all sides of the conflict risks fuelling intercommunal violence.”
Mr Price said Mr Blinken called on Mr Mekonnen to "urgently and seriously engage in negotiations" and "underscored the need for immediate unhindered humanitarian access to northern Ethiopia".
Also this week, Amnesty International and Human Rights Watch released reports detailing how fighters from the TPLF have used rape and sexual violence as a weapon of war.
The Amnesty International report said that rebel fighters raped and beat 16 women in Ethiopia’s Amhara region in August.
The war in Tigray enters its second year
An Amnesty International report in August found that Ethiopian forces loyal to Mr Abiy and their allies had “subjected hundreds of women and girls to sexual violence".
Ethiopia has maintained an internet, phone and media blackout in Tigray since the conflict erupted last year between the TPLF and Ethiopian forces, backed by Eritrean troops and Amhara militias.
Witnesses have described widespread human rights abuses in Tigray, including the displacement and murder of civilians, gang rapes, the destruction of civilian infrastructure and the burning of crops.
The US State Department is considering whether Ethiopian actions in Tigray amount to genocide and Washington is poised to kick Ethiopia out of the African Growth and Opportunity Act trade pact.
