The UN's top humanitarian official has said it is vital that UN peacekeepers are allowed into Sudan's Darfur region to help end the humanitarian crisis.
Speaking from Darfur, Jan Egeland told the BBC there was a sea of militias in the region and without security the humanitarian work could not succeed.
Mr Egeland is in Darfur, in western Sudan, to assess conditions there and in refugee camps in neighbouring Chad.
He is to hold talks with the government in the capital, Khartoum, on Monday.
The government and the biggest rebel group signed a peace deal on Friday.
The agreement has raised hopes the government will allow UN peacekeepers to take over from African Union troops in the region. It has previously said it would only consider doing so if a peace deal was signed.
Some 7,000 African Union troops are in the region - an area the size of France - but have struggled to contain the fighting.
"At the moment Darfur is slowly being strangled, it's dying in front of us," said Mr Egeland, the UN's Emergency Relief Co-ordinator.
DARFUR PEACE PLAN
Pro-government Janjaweed militia to be disarmed
Rebel fighters to be incorporated into army
One-off $300m transfer to Darfur
$200m a year for the region thereafter
Compensation for those forced to flee their homes
Regional government, if approved in a vote
"Half of the population now has become war victims...so I believe, yes, we are turning the corner, but the whole world has to put pressure on the parties."
He was speaking in the town of Gereida which is held by the rebel group which signed the peace deal, the Sudan Liberation Movement under Minni Minnawi.
Just a month ago, the government banned Mr Egeland from visiting Darfur.
Tens of thousands of people around Gereida have been displaced in recent weeks, and the UN has warned of an impending disaster.
Earlier, Mr Egeland held talks with the deputy governor of South Darfur in the town of Nyala and called for aid workers to be given unlimited access, as agreed in the peace deal.
On his arrival at Nyala airport he was greeted by a small government-backed anti-UN demonstration.
The peace plan, brokered by the African Union, creates a temporary regional government for Darfur, in which rebels will take part.
But two smaller rebel groups rejected the agreement.
The three-year conflict has killed about 200,000 people and left about two million homeless.
Aid organisations say the conflict has created one of the world's worst humanitarian crises.
Money for the world's largest aid operation is running out. Rations for May have been cut in half and many of Darfur's 2m displaced people will go hungry.
The BBC's Jonah Fisher says Khartoum appears to be sending out mixed messages on the issue of whether to allow UN peacekeepers into the region.
The rebels took up arms in 2003, accusing the government of discriminating against the black African residents of Darfur.
Pro-government Arab militia then launched a campaign, described as "genocide" by the US.
The Sudan government denies backing the Janjaweed militias accused of mass killing, rape and looting.