UN chief Kofi Annan led a push on Thursday for a "hybrid" force of African Union and United Nations peacekeepers to be allowed into Darfur amid reports of new violence in Sudan's war-shattered region.
But as the meeting in Ethiopia dragged into the evening, Khartoum again seemed set on rejecting the latest UN plan to end the Darfur bloodshed despite the outgoing secretary-general's personal efforts.
"It is not good to put things in terms of what you will accept or won't accept. Things are not hard and fast like that," Sudanese Foreign Minister Lam Akol said in Addis Ababa.
On his farewell trip to Africa, Annan convened UN Security Council, EU, Arab League and African Union officials to try to break the deadlock over international troops in Darfur.
Violence has continued in Sudan's arid west where AU peacekeepers have been unable to control the fighting. Before Thursday's meeting began, Sudanese rebels accused government troops and militias of killing more than 50 people in an attack on their positions in north Darfur.
And the Sudanese government told UN humanitarian chief Jan Egeland all his proposed destinations on a three-day trip to Darfur were too insecure to visit. Violence in Darfur has raged since 2003, with some 200,000 people killed and more than 2.5 million driven from their homes.
The head of one faction of the rebel Sudan Liberation Army (SLA), said government troops, backed by allied Janjaweed militia, attacked its positions in the Deir Mazza area on Wednesday, killing several rebels and the rest civilians.
The government had used fighter planes, Abdel Wahed al-Nur told Reuters, calling the attack "a massive escalation from the government" which would bring an SLA response. A Sudanese army spokesman, who declined to be named, said the report was "100 percent incorrect". There was no immediate word from the AU, whose 7,000-strong Darfur force is struggling to monitor a land the size of France. As Egeland arrived there on Thursday, security was so bad he could not visit camps outside el-Geneina town housing tens of thousands of terrified Darfuris.