For weeks, the U.N. and others have pleaded for aid access amid reports of food, medicines and other supplies running out for millions of people.

A U.N. humanitarian spokesman, Saviano Abreu, said the first mission to carry out a needs assessment begins Wednesday after the agreement was signed this week.

“We are of course working to make sure assistance will be provided in the whole region and for every single person who needs it,” he said. The U.N. and partners are committed to engaging with “all parties to the conflict to ensure that humanitarian action in Tigray, Amhara and Afar regions be strictly based on needs and carried out in compliance with the globally agreed upon principles of humanity, impartiality, independence and neutrality.”

For weeks, aid-laden trucks have been blocked at Tigray’s borders, and the U.N. and other humanitarian groups were increasingly anxious to get unfettered, neutral access to Tigray as hunger grows and hospitals run out of basic supplies like gloves and body bags.

“We literally have staff reaching out to us to say they have no food for their children,” one humanitarian worker told The Associated Press. The person spoke on condition of anonymity because of the sensitivity of the situation.

More than 1 million people in Tigray are now thought to be displaced, including over 45,000 who have fled into a remote area of neighboring Sudan. Humanitarians have struggled to feed them as they set up a crisis response from scratch.

Communications and transport links remain almost completely severed to Tigray, and the fugitive leader of the defiant regional government this week told the AP that fighting continues despite Prime Minister Abiy Ahmed’s declaration of victory.

It remains almost impossible to verify either side’s claims as the conflict threatens to destabilize both the country and the entire Horn of Africa.

“It is critically important to get objective information as to what is going on,” the top U.S. diplomat for Africa, Tibor Nagy, told the BBC. “The active military phase is basically over. I’m not saying the fighting is over. So at this point, the humanitarian phase is the most important one.”

For weeks, the U.N. and others have been increasingly insistent on the need to reach some 600,000 people in Tigray who already were dependent on food aid even before the conflict.

Now those needs have exploded, but Abiy has resisted international pressure for dialogue and de-escalation, saying his government will not “negotiate our sovereignty.” His government regards the Tigray regional government, which dominated Ethiopia’s ruling coalition for more than a quarter-century, as illegitimate after months of growing friction as he sought to centralize power.

Amid the warring sides’ claims and counter-claims, one thing is clear: Civilians have suffered.

The U.N. says food has run out for the nearly 100,000 refugees from Eritrea whose camps close to the Tigray border with Eritrea have been in the line of fire as the fighting swept through. Reports that some refugees have been killed or abducted, if true, “would be major violations of international norms,” the U.N. refugee chief said over the weekend in an urgent appeal to Abiy.

With infrastructure damaged, the U.N. has said some people in Tigray are now drinking untreated water, increasing the risk of diseases.

In northern Ethiopia’s largest hospital in the Tigray capital of Mekele, staff had to suspend other activities to focus on treating the large number of wounded from the conflict, and body bags have run out, the International Committee for the Red Cross says.

The ICRC, the rare organization to travel inside the Tigray region and its borderlands, has reported coming across abandoned communities and camps of displaced people.

No one knows the true toll of the fighting. Human rights and humanitarian groups have reported several hundred people killed, including civilians, but many more are feared.

Inside Tigray, and among the majority ethnic Tigrayan refugees in Sudan, people are exhausted.

“The world hasn’t seen anything like this year. I have never seen anything like this,” said one refugee who gave his name as Danyo, standing on the edge of a river that people on Tuesday were crossing to seek safety.

“When Dr. Abiy came, we saw him as a good thing,” he said. “Our hopes were fulfilled, because his talk in the beginning was as sweet as honey, but now the honey has gone sour.”