The humanitarian situation in Sudan's Darfur region is as bad now as when the conflict came to the world's attention in 2004, the top UN aid official says.
Refugees are still being attacked in camps, Mr Egeland said
Jan Egeland told the BBC that aid workers in Darfur were "in retreat" from attacks by armed groups, a funding shortfall and government obstacles.
He said that 500,000 people of the 3m who needed help were "out of reach".
The US says a genocide is being committed against Darfur's black African population.
Sudan's governments has consistently said the scale of the problems are being exaggerated for political reasons.
It denies backing the Arab Janjaweed militias accused of mass rape, killing and looting.
Asked whether international focus on bringing to justice those accused of atrocities was distracting from the aid effort, Mr Egeland said that more pressure might be needed to solve the problems in Darfur.
He had earlier briefed the United Nations Security Council on the situation in Darfur.
Earlier this month, the Sudanese government prevented Mr Egeland from visiting the region.
Meanwhile, lobby group Human Rights Watch has urged the UN to take control of the peace mission in Darfur.
"A UN mission could help to stop the atrocious attacks on civilians in Darfur, but only if it is given the means to act aggressively," said Peter Takirambudde, Africa director for Human Rights Watch.
"It needs a tough mandate, real resources and political support."
Sudan opposes such moves, saying an extra funding should instead be given to the 7,000 hard-pressed African Union peacekeepers already in Darfur.
On Thursday, International Committee of the Red Cross Sudan spokesman Paul Conneally said that aid workers could not operate in large parts of Darfur because of ongoing fighting.
He said tens of thousands of people had recently been forced from their homes around the rebel bases in the Marra mountains.
Darfur's rebel groups are now fighting each other
He said the fighting was heavy and confused, with pro-government Arab militia attacking civilians, while factions of the main rebel movement, the Sudan Liberation Army, are also clashing with each other.
"The town of Golo is deserted," he said, adding that it used to have 20,000 inhabitants.
Earlier this week, the UN said Sudan had not granted visas to its military assessment team, who were due to travel to Darfur ahead of a possible UN takeover of the peacekeeping mission.
Sudan wants the visit to be postponed until after peace talks with the rebels are finalised in Nigeria.
The African Union (AU), which currently runs the peace mission, has set a deadline of 30 April for the two sides to reach a deal.
But the UN says it would continue to plan for a possible deployment.
The Security Council is considering a draft resolution on possible sanctions against four Sudanese accused of atrocities in Darfur.
Russia and China have said they will oppose the UK and US suggestion of imposing a travel ban and assets freeze on the four, reportedly including both rebels and officials.