The UN has called for an independent investigation into reports of human rights abuses in Ethiopia's predominantly Somali Ogaden region.
Aid agencies say roads have been closed
A visiting UN group says they found a pervasive fear among residents caught in clashes between the army and rebels.
The Ethiopian army has been accused by ONLF separatists of operating a food blockade and causing a man-made famine.
Responding to the report, Ethiopia said it would work with the UN to ensure the region's food requirements were met.
However, it did not comment on allegations of abuses.
The report by the mission, who visited the area last month, also calls on the government to give aid agencies access to the region.
It says the food situation is deteriorating rapidly and could reach emergency levels very shortly and that there is an acute shortage of drugs and other medical supplies in the area.
The BBC's Elizabeth Blunt in Addis Ababa says that the fact that the mission decided not to make the report public but to share the findings privately with the government suggests that publication would have caused considerable embarrassment and prejudice the chance of getting matters improved
The UN says emergency food aid is required for some 600,000 people for the next three months.
International aid agency Medecins sans Frontieres early this month said a disaster is looming in the region after it was denied access to the masses by the government.
The Ogaden National Liberation Front want independence
UN officials further warn that humanitarian conditions in the conflict zone have deteriorated substantially.
It says the food situation is deteriorating rapidly, there are acute shortages of drugs and other medical supplies and what relief food has reached the region is being distributed by the army with no proper procedures to make sure it reaches the people most in need.
In its response, the Ethiopian government summarises the report by saying that the UN mission found no humanitarian crisis in the Somali region.
It does however promise to ensure that the food and medical needs of the people in the region are met in collaboration with UN agencies and other partners.
It makes no comment on the UN's assertion that human rights concerns in the Ogaden require urgent and independent investigation.
"The main point is that the report is confirming what the government is thinking especially about the humanitarian situation in this region," government spokesman Wahide Beleye told AFP news agency.
The ONLF was founded in 1984 and is fighting for independence from Ethiopia, complaining of discrimination by the central government against the region's Somali-speaking nomads.