The UN children's fund said huge numbers of children had died because of food shortages and human rights abuses caused by the war, and that many more would follow them to the grave.

The UN's World Food Programme has said it is unable to deliver food aid to more than a million people because renewed fighting between Unita rebels and government troops have made roads and airports too dangerous.

The BBC's Jane Standley reports: "What used to be an ideological cold war is now a conflict about money"

Earlier, the Angolan Government refused a request by the UN Security Council for humanitarian corridors to allow aid workers safe passage.

Foreign Minister Joao Miranda said there was no need for such measures, because the government would itself ensure the distribution of emergency aid to the people who needed it.

Unita rebels have yet to respond to the UN appeal, which followed a report that 200 people were dying each day, cut off from assistance because of the fighting.

Worst place to grow up

In a statement issued on Wednesday, the UN Children's Fund said that Angola is the "the country whose children are at the greatest risk of death, malnutrition, abuse and development failure".

It warns that "without an immediate cessation in hostilities and a massive humanitarian response ... large numbers of Angola's children will perish".

The suffering is immense

However, the prospects for peace look remote.

Unita leader Jonas Savimbi said in a BBC interview broadcast on Tuesday that both sides were strong enough to fight for long enough to destroy Angola.

He did say that Unita was ready for talks with the government at any time, but only last week, Angolan President Jose Eduardo dos Santos said there was no point in talking to Unita and the only way to resolve the war was through force.

The government have branded the Unita leader a war criminal, and last month issued a warrant for his arrest.

Government offensive?

There have been reports of heavy fighting between government troops and Unita rebels in Uige province.

Richard Dowden, Africa specialist from the Economist magazine

Aid workers say they have seen large numbers of government troops heading towards the province.

Diplomats have interpreted the move as a possible sign of a new government offensive in the central highlands, the Unita leader's base.