UN warns of worsening famine in Ethiopia's Tigray

and that there was a risk of more clashes in the region despite a unilateral ceasefire by the federal government.

After six private discussions, the Security Council held its first public meeting since fighting broke out in November between government forces, backed by troops from neighboring Eritrea, and TPLF fighters with Tigray's former ruling party.

Acting U.N. aid chief Ramesh Rajasingham told the council that the humanitarian situation in Tigray had "worsened dramatically" in recent weeks with an increase of some 50,000 in the number of people now suffering famine.

"More than 400,000 people are estimated to have crossed the threshold into famine and another 1.8 million people are on the brink of famine. Some are suggesting that the numbers are even higher. 33,000 children are severely malnourished," he said.

The Ethiopian government declared a unilateral ceasefire on Monday, which the TPLF dismissed as a joke. There are reports of continued clashes in some places as pressure builds internationally for all sides to pull back.

U.S. Ambassador to the United Nations, Linda Thomas-Greenfield, said Ethiopia's government "must now demonstrate that it truly intends to use the ceasefire to address the humanitarian catastrophe." She also urged all parties to negotiate and honor "a true ceasefire."

"If the parties to the conflict failed to seize this moment, the consequences for the people of Ethiopia, will be devastating. More fighting, more famine, more abuses, more suffering by ordinary Ethiopians and a far more destabilized Horn of Africa," Thomas-Greenfield told the council.

U.N. political and peacebuilding affairs chief Rosemary DiCarlo said Eritrean forces had withdrawn to areas adjacent to the border and that forces from the neighboring region of Amhara remained in areas of western Tigray that they had seized.

"In short, there is potential for more confrontations and a swift deterioration in the security situation, which is extremely concerning," she told the council.

She urged the TPLF to endorse the ceasefire "immediately and completely" and for the Eritrean troops to fully implement their withdrawal.