The United Nations says it and Ethiopia's government have signed a deal to allow "unimpeded" humanitarian access to the embattled Tigray region, at least the parts now under federal government control, after the prime minister's declaration of victory in the deadly conflict over the weekend. The deal will allow the first aid into the region of 6 million people that has been cut off during fighting that began a month ago between the federal and Tigray regional governments. Each regards the other as illegal in a power struggle that has been months in the making. 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.