Neither demand may be fulfilled. Talks led by the African Union between Sudan and Darfur rebels in Abuja, Nigeria, have not been decisive, although the aim is a deal by April 30.

And Sudan may reject the demand for a UN military assessment mission to go to Darfur by April 30. The Sudanese have not agreed to future UN peacekeepers in Darfur.

The 15-nation Security Council, in a policy statement read at a public meeting, backed the African Union's April 30 deadline for reaching an agreement in the Abuja talks and reaffirmed its decision "to hold accountable those impeding the peace process and committing human rights violations".

Failures

The Abuja negotiations have missed several deadlines already, but this time African heads of state and Sudanese officials are intervening.

The chairman of the AU (L) and
Obasanjo at talks in Abuja

The Darfur conflict erupted in early 2003 when various tribes took up arms, accusing the Khartoum government of neglect.

The government retaliated by arming militia, known as Janjawid, who began a campaign of murder, arson and plunder that drove two million villagers into squalid camps. Khartoum denies responsibility. The Janjawid are not part of the Abuja talks.

The main bulwark against abuses is the cash-strapped African Union which, under pressure from its Arab members who side with Khartoum, is hesitating to merge its 7,000 troops with a UN force.

Sudan recently refused a Darfur visit by Jan Egeland, the UN humanitarian co-ordinator, and refused to renew the contract of the Norwegian Refugee Council that cares for 90,000 people driven from their homes.

Action

The council's statement, agreed to by all 15 members, expressed regrets at both decisions.

A senior UN peacekeeping official, Hedi Annabi, expects to go to Khartoum shortly, diplomats said. In addition, Salim Ahmad Salim, the AU's mediator for the Darfur talks, will visit the United Nations next week.

"The next step, of course, will be on
the issue of sanctions against individuals
in the Sudan"

John Bolton,
US ambassador to the UN

Diplomats have said Britain will soon distribute a list of individuals it believes are blocking the peace process, who could become the targets of UN sanctions, such as a travel ban and having their foreign assets frozen. But China, which has veto power, has said it is not in favour of sanctions.

John Bolton, the US ambassador to the UN, said: "The next step, of course, will be on the issue of sanctions against individuals in the Sudan, where we expect to make progress this week."

Separately, Kofi Annan, the UN secretary-general, through his spokesman, expressed deep concern about recent fighting along Chad's border with Sudan which has spilled over into the Central African Republic.

He condemned recent attacks against refugee camps in southern Chad, where Sudanese from Darfur have fled, and the killing of two doctors on a humanitarian mission supported by the United Nations, in the northern Central African Republic.