The UN on Thursday said more than $1 billion in funding was needed this year to help millions of people affected by Boko Haram's Islamist insurgency in northeast Nigeria.
The humanitarian co-ordinator in Nigeria, Edward Kallon, said "life-saving emergency assistance to the most vulnerable" in Borno, Yobe and Adamawa states was the "immediate priority".
Funding would also go towards improving the quality of programmes already in place and increasing the ability of local agencies to respond in the longer term, he added.
"In doing so, humanitarian partners will require $1.05 billion to reach 6.1 million people with humanitarian assistance," he said in the foreword to the 2018 Humanitarian Response Plan.
Launching the document in Abuja, Kallon said some 70 percent of last year's appeal for $1 billion in funding was met, making Nigeria "one of the best-funded appeals globally".
A total of $196 million has been carried over and will go towards programmes providing food, shelter, clean water, education for out-of-school children and medical care.
But Kallon said: "Most of the carry-over will be exhausted in the first quarter of the year".
The UN and other aid agencies have previously warned about the potential effects of under-funding the humanitarian response to the insurgency.
At least 20,000 people have been killed since 2009 and more than 2.6 million have been forced into camps for the displaced or to stay with distant family or friends elsewhere in Nigeria.
Others have fled across the border into Cameroon, Chad or Niger.
A counter-insurgency launched in early 2015 has succeeded in recapturing territory lost to Boko Haram but has exposed the extent of the effects of the violence on the population.
"Famine-like" conditions were found in many places where farmland had been destroyed and access was impossible, while there were warnings that hundreds of thousands faced starvation.
International aid agencies were forced to make cuts in the first half of last year because of funding shortfalls.
The report said that despite improvements in international and domestic aid since then, the situation remained "fragile" and longer-term solutions were needed.
"Millions are vulnerable to severe food insecurity as any disruption of the food pipeline may cause people to again slip below emergency thresholds," he added.
A total of 943,000 children under five were still acutely malnourished. Of those, 440,000 had severe acute malnutrition and one in five were at risk of death, it added.