A senior United Nations official has warned that the Sudanese region of Darfur is on the brink of a new humanitarian disaster.

The UN's Emergency Relief Co-ordinator, Jan Egeland, told the UN Security Council that the work of aid agencies could collapse because of a chronic lack of security.

His warning came as the UN Security Council met to consider a proposal by the US and Britain to send 20,000 UN troops to Darfur.

Mr Egeland said safer conditions for aid workers are needed.

The UNSC meeting was boycotted by the Sudanese government, which has so far resisted pressure to allow the deployment of UN troops.

The proposed UN force would take over from an ill-equipped and under-funded African Union mission. The AU force has proved unable to prevent killings and internal displacement of civilians in the region.

US Ambassador to the UN John Bolton said the absence of Sudan in the UNSC talks was 'disappointing', but insisted Washington and London would press for a vote on their troop proposal before the end of the month.

The deployment of UN peacekeepers is seen as crucial to bolstering a fragile Darfur peace deal signed in May.

Decades of ethnic tensions in Darfur erupted into violence in 2003 when ethnic minorities took up arms against the Arab-dominated government in Khartoum in a fight for autonomy and a greater share of the country's resources.

Fighting in the region has left at least 300,000 people dead and 2.5 million homeless since 2003.