Eltigani Seisi made the comments on Sunday in an interview with AFP ahead of an April 7 to 8 donors' conference in Qatar.
Analysts are sceptical that major funds will be forthcoming.
"If the international community refrains from providing support then how could we be able to stabilise the situation on the ground?" Seisi said.
"And how could the people of Darfur have dividends for peace?"
United Nations secretary general Ban Ki-moon reported in January that a 2011 armistice deal, signed in Doha, has yet to bring "concrete peace dividends" for Darfur's neediest.
The UN says 1.4-million still live in camps for people displaced by fighting.
"I am increasingly concerned that this lack of meaningful progress will erode the confidence of the people of Darfur and the international community in the Doha document," Ban said.
He called it "particularly regrettable" that provisions for the voluntary return of the displaced, the disbanding of militia and reconstruction and development have not been implemented.
Sudan's government signed the peace deal with an alliance of rebel splinter factions but major insurgents rejected it.
Inter-Arab violence
The rebellion, by groups complaining about an imbalance of power and wealth in the country, has been compounded by inter-Arab violence, banditry and tribal fighting.
Seisi heads the Darfur Regional Authority set up to implement the Doha agreement.
He said the Khartoum government, after delays, has now transferred an initial contribution of about $200-million for a reconstruction and development fund. Seisi had earlier described the payment as "absolutely necessary" to persuade other contributors.
Sudan's economy has struggled after losing about half its fiscal revenues when South Sudan separated in 2011 with most of the united country's oil production.
"The issue is provision of services as well as infrastructure development" for Darfur, Seisi said. "That development cannot come through without the support of the international community."
An assessment mission under the peace agreement concluded that Darfur needs about $6-billion for economic recovery, development and poverty eradication, he said.
The extent to which the international community will deliver fresh funding is unclear, a foreign diplomat said.
"I'm not very optimistic," said the diplomat, requesting anonymity.
"It all depends on the donors," Seisi said.
Restrictions on international aid
Dane Smith, the US administration's senior adviser for Darfur, warned in December that financial support for Darfur's recovery is in jeopardy unless the Khartoum government eases restrictions on international aid personnel.
He said they face difficulties in getting visas and permits to reach Darfur.
Seisi said he is "very much concerned" the issue could limit funding but authorities are taking steps to improve access.
"I don't see any reason for not allowing UN staff to go there", he said.
The United Nations said last Thursday that aid delivery is in jeopardy for an estimated 100 000 people affected by violence in the Jebel Amir region of North Darfur state unless authorities grant better access.
The mass displacement occurred after inter-Arab tribal fighting in a gold mining area of North Darfur, a state where "ethnic tensions" have led to recent violence, Seisi said.
He admitted that government-linked militia in North Darfur have "committed atrocities against innocent civilians" but he said the Doha peace deal calls for militia to be disbanded.
Elsewhere in Darfur, "we believe the situation has improved a lot," he said. – Sapa