A draft Security Council resolution to authorise deploying a joint UN-African Union peacekeeping force in Sudan's Darfur region has been watered down.
African Union peacekeepers have been unable to end the fighting
The wording of the new text drops the threat of sanctions if Sudan fails to comply with the resolution.
The UK and France circulated the weakened draft ahead of formal Security Council negotiations on Wednesday.
They hope it will assuage the concerns of African council members, but Sudan maintains the new draft is "very ugly".
The resolution proposes that a combined force of 26,000 soldiers and police take over from the AU force in Darfur at the end of December.
A small AU force has failed to halt the violence, which the UN says has led to some 200,000 deaths and seen more than 2m displaced.
The UN World Food Programme (WFP) says there has been a dramatic escalation in attacks on humanitarian staff and food convoys in Darfur, which is hampering its ability to deliver assistance.
The new draft leaves intact provisions that would allow the joint UN-African Union contingent to use force in carrying out its duties.
WFP ATTACKS: 2007
18 food convoys attacked by gunmen
10 staff, including contractors, detained or abducted
4 light vehicles carjacked
6 vehicles stolen
"We changed the text quite considerably. The tonality has changed... I think there is less threatening language in there," AFP news agency quotes the UK's UN ambassador Emyr Jones Parry as saying.
But Sudan's UN ambassador Abdalmahmood Abdalhaleem Mohamad said his country objected to the revised draft saying it still contained "hostile language", AP news agency reports.
"The way they put this resolution will make the force fight the Sudanese army. They want to transport the Iraqi scenario to us," he said, Reuters news agency reports.
Last month, the Sudanese government agreed to allow the hybrid force into the region after months of pressure from the international community.
Meanwhile, the WFP has called on all parties in the conflict to guarantee the safety of humanitarian workers in Darfur.
"In the last two weeks, nine food convoys have been attacked by gunmen across Darfur," said the WFP's Kenro Oshidari.
"WFP staff and contractors are being stopped at gunpoint, dragged out of their vehicles and robbed with alarming frequency.
"These abhorrent attacks, which target the very people who are trying to help the most vulnerable in Darfur, must be brought under control," he said.
Following talks in Libya this month, the UN and AU have asked the rebel factions that did not sign a failed 2006 peace deal to attend talks in Tanzania early in August.