The African Union (AU) has said it backs proposals for a UN peacekeeping force in the Darfur region of Sudan, despite opposition from its government.
The African Union says it may have to withdraw troops for lack of funds
A senior AU official told the BBC it was not down to Sudan to dictate what action was taken to end violence there.
Sudan's foreign minister earlier said money spent sending a UN force would be better used helping the current AU one.
The AU has warned the UN that it may be forced to hand over its Darfur peace mission because of a lack of funds.
UN Secretary General Kofi Annan has called for plans to deploy a new, Western-backed rapid reaction force with air support and sophisticated equipment.
He said rapes and murders were continuing in the region, where a civil war and militia raids have forced some two million people to flee their homes in the past three years.
Sudanese Foreign Minister Lam Akol told the BBC the UN had no business proposing a new force without Khartoum's approval.
However, the deputy chairman of the AU Commission suggested the AU might take a tougher line than expected with Sudan.
"The government of Sudan obviously cannot be the one to make a choice about this," Patrick Mazimphaka told the BBC.
He said the AU mission in Darfur and observers on the ground were better placed to assess what was needed.
The BBC's Africa editor Martin Plaut says that if this position is backed by the African heads of state, it will mark a very real change in the status of the AU itself.
Until now the AU, founded in 2002, has hesitated to invoke a clause allowing it to intervene in the internal affairs of a member state in order to prevent war crimes, genocide and crimes against humanity, he says.
Now it appears ready to act, our correspondent says, which will give added significance to the AU summit due to open in Khartoum next week.
The AU has some 6,000 peacekeepers in Darfur but says they are under-resourced and may have to be withdrawn.
The UN special representative in Sudan, Jan Pronk, earlier told the Security Council that at least once a month, groups of up to 1,000 militia on horseback kill and terrorise local people.
He said the current peace strategy had failed, and a bigger, stronger force should go to Darfur.
Sudan has accused Western nations, such as the US, of exaggerating the problems in Darfur for political reasons.
In recent months, AU troops in the region have been attacked by gunmen. It is not clear who was behind these attacks.
Peace talks between the government and Darfur rebels have dragged on for many months without ending the conflict.
The rebels say the army and pro-government Arab militias are responsible for the continued violence.
Sudan's government has said that the violence in Darfur is a tribal conflict and the attacks are carried out by militias and rebels.