Originally Published: 20 MAR 23 13:27 ET

By Michael Conte and Kylie Atwood, CNN

(CNN) -- US Secretary of State Antony Blinken said Monday that the US has formally determined that armed forces on all sides of the conflict in northern Ethiopia have committed war crimes.

"After the department's careful review of the law and the facts, I've determined that members of the Ethiopian National Defense Forces, Eritrean Defense Forces, Tigray People's Liberation Front forces and Amhara forces committed war crimes during the conflict in northern Ethiopia," Blinken said at a press conference for the release of the State Department's 2022 Human Rights Report.

Blinken traveled last week to Ethiopia where he met with leaders and he did not raise the war crimes determination.

"As I discussed with both sides during my visit, to build a durable peace, there must be acknowledgment of the atrocities committed by all parties, as well as accountability, together with reconciliation," Blinken said.

He said the determination "is a product of a lot of very deliberate and detailed work" and that it seemed appropriate to make the announcement now as the department is putting out its human rights report.

Blinken also accused "members of the Ethiopian National Defense Forces, the Eritrean Defense Forces and Amhara forces ... committed crimes against humanity, including murder, rape and other forms of sexual violence and persecution."

He also accused the Amhara forces of "the crime against humanity of deportation, or forcible transfer, and ... ethnic cleansing through their treatment of Tigrayans in western Tigray."

Blinken said that the US "will partner with Ethiopia as it implements a credible transitional justice process for the benefit of all victims and affected communities." Just last week, US officials who participated in a workshop with Ethiopian government officials on transitional justice with other international specialists, he said.

He also praised steps the Ethiopian government has taken towards transitional justice.

"The government of Ethiopia is taking the first steps by publicly releasing a detailed green paper with transitional justice options based upon best practice and building upon the experiences of other states emerging from periods of mass violence," said Blinken.

Blinken also said the Ethiopian government has invited UN human rights monitors "to ensure that such acts have truly ceased" and is holding "public consultations about transitional justice."

"The process is benefiting from the advice of experts in the field, including members of my team who participated in a workshop on transitional justice with other international specialists just last week," said Blinken.

Blinken pressed Ethiopian Prime Minister Abiy Ahmed last week on accountability for atrocities committed by all parties in the conflict.

The determination comes months after the Abiy government and the Tigray People's Liberation Front reached a "permanent cessation of hostilities agreement" aimed at ending the bloody dispute that caused a humanitarian catastrophe and led to a significant rift in the relations between the United States and Ethiopian governments.

CNN reported extensively on mass killings and acts of sexual violence that were committed during the course of the conflict, some of which bear the hallmarks of genocide. Blinken said in late 2021 that the US would make a determination about whether the crimes committed in northern Ethiopia constitute genocide "once we get all the analysis that goes into looking at the facts and looking at the law."

A joint report released in late 2021 by the Office of UN Commissioner for Human Rights and the Ethiopian Human Rights Commission found that all parties to the conflict had "committed violations of international human rights, humanitarian and refugee law, some of which may amount to war crimes and crimes against humanity."

Over the last two years, the Biden administration enacted some punitive measures in response to the war. In November 2021, they imposed sanctions on Eritrea's military and its sole political party for their involvement in the conflict. At the start of 2022, Ethiopia lost access to a lucrative US trade program called the African Growth and Opportunity Act due to "gross violations of internationally recognized human rights."