By Susannah Price
BBC UN correspondent
Senior United Nations officials have condemned the killings in the Darfur region of western Sudan - but have stopped short of describing it as genocide.
Tens of thousands of people fled Darfur
UN Secretary General Kofi Annan, who is due to visit the country in the next few weeks, has said there were massive violations of international humanitarian law being committed there.
However, international aid agencies have accused the UN of being slow to react to the crisis which has left thousands dead and forced more than a million to flee their homes.
The UN Under Secretary General for Humanitarian Affairs, Jan Egeland, has said there is ethnic cleansing underway and accused elements in the government from preventing efforts to bring aid to the people of Darfur.
Human rights organisations say government forces and Arab militias have been attacking African civilians from the same ethnic groups as rebel forces in the area.
The Sudanese government says they are not involved and blame the militias.
Mr Annan says he did not have any specific evidence but from all accounts the Sudanese government could do something about the Janjaweed militias.
The UN Security Council passed a resolution earlier this month calling on the parties to use their influence to bring an immediate halt to the fighting.
Germany, Britain and the United States say they are very keen to draw maximum attention to Darfur - but other members such as China and Pakistan were less enthusiastic.
Last month, the Security Council issued a strong Presidential Statement speaking of indiscriminate attacks on civilians, sexual violence, forced displacement and acts of violence and calling for those responsible to be held accountable.
It also called on the parties to protect civilians and facilitate humanitarian access.
Aid groups say the Security Council must make sure that Sudan complies with these demands and there should be credible threats of action if it does not comply such as sanctions.
Annan is shortly due to visit Sudan
"There needs to be really serious pressure because the government is capable of controlling a large amount of this violence," said Joanna Weschler, Representative at the UN for Human Rights Watch.
Mr Annan has hinted at the possibility of military intervention although it is not seen as likely.
It is not clear what the next step is likely to be at the UN.
There is a huge effort on the humanitarian side with UN officials warning that with the rainy season about to start, it is a race against time to provide basic services.
On the political front, it appears that the Sudanese will be given some time to show that they are taking steps to control and disarm the militias.
However, 10 years after the genocide in Rwanda, the United Nations knows the world will be watching its actions very carefully.