US President Joe Biden condemned the six-month conflict in Ethiopia's war-hit Tigray region Wednesday, calling for a ceasefire and declaring that human rights abuses "must end."

"I am deeply concerned by the escalating violence and the hardening of regional and ethnic divisions in multiple parts of Ethiopia," Biden said in a White House statement. "The large-scale human rights abuses taking place in Tigray, including widespread sexual violence, are unacceptable and must end."

Ethiopian Prime Minister Abiy Ahmed initially sent troops into Tigray in November after accusing the once-dominant regional ruling party of orchestrating attacks on federal army camps.

Abiy, a Nobel Peace Prize winner, declared victory later that month when the army entered the regional capital Mekele.

But fighting continues and the half-year conflict has sparked allegations of massacres and rape by Ethiopian forces and troops from neighboring Eritrea.

"Belligerents in the Tigray region should declare and adhere to a ceasefire, and Eritrean and Amhara forces should withdraw," Biden said, referring to the Amhara region, which borders Tigray to the south.

Earlier this week UN aid chief Mark Lowcock warned the Security Council that "there is a serious risk of famine if assistance is not scaled up in the next two months."

Based on the warning, Biden said, "all parties, in particular the Ethiopian and Eritrean forces, must allow immediate, unimpeded humanitarian access to the region in order to prevent widespread famine."

For the first time on Wednesday Abiy's government disclosed the toll of attacks by Tigrayan forces, who federal officials have long claimed would be unable to mount an effective insurgency.

Ethiopia said it had recorded 22 dead officials, 20 others who had been "kidnapped," and four more who were "wounded and hospitalized."

Some of the conflict's worst atrocities, including mass rapes and massacres, are believed that have left hundreds dead.

"The government of Ethiopia and other stakeholders across the political spectrum should commit to an inclusive dialogue," Biden said, urging the country's leaders and institutions to "promote reconciliation, human rights, and respect for pluralism."

"The United States is committed to helping Ethiopia address these challenges," Biden said, indicating that US special envoy for the Horn of Africa Jeffrey Feltman would return to the region next week.