A UN-appointed commission has arrived in Sudan to decide whether genocide has taken place in the region of Darfur.
The talks have come unstuck over no-fly zone proposals
The five-member panel has three months to reach a conclusion.
The United States has already called the situation in Darfur genocide but the Sudanese say the US declaration is politically motivated.
African Union mediators have been meeting separately with Sudanese government and Darfur rebels in ongoing peace talks in Abuja, Nigeria.
Speaking to the BBC, Sudanese Foreign Minister Mustafa Uthman Isma'il said Khartoum welcomed the commission's arrival because it was confident that no genocide had taken place.
Mr Isma'il said the US was the only country to assert genocide had occurred in Darfur and blamed rebels for the humanitarian, security, and political problem there.
A UN spokesman in Sudan, George Somerwill, said the body's mandate is to investigate of reports of violations of international law and human rights law in Darfur "by all parties" and to determine "whether or not acts of genocide have occurred and to identify the perpetrators of such violations".
Italian judge Antonio Cassese heads the body.
On Monday, AU mediators continued separate neogotiations with Sudanese government officials and rebel representatives in Abuja.
The talks had stalled last week over the question of creating a no-fly zone over the area.
The UN commission is due to meet Sudanese officials in Khartoum before flying to Darfur later this week, Sudanese media reports.
Some 1.6 million people have fled their homes and 70,000 have been killed since the conflict began in early 2003.
The UN's Security Council is also examining a new UN resolution expected to be adopted when it meets in Nairobi later this month.
Correspondents say the new UN draft resolution looks more towards promises of help for Sudan, rather than threats of punishment.
Aside from Darfur, it backs efforts to end the war between Khartoum and the southern rebels. The two sides have signed important deals, clearing the way for a full treaty possibly by the end of the year.
The resolution says once a north-south peace deal is signed, the UN will send in a peacekeeping operation.
The Security Council has passed two resolutions already, threatening sanctions against Sudan's government if the violence in Darfur continues. But it has had little discernible effect.
Pro-government Janjaweed militias are accused of driving the region's black Africans from their villages, since two rebel groups began an uprising in February 2003.
Aid agencies in south Darfur have evacuated some areas as clashes between rebels and the government continue.
The Spanish branch of Medecins Sans Frontieres said on Sunday it had withdrawn its staff from the Jebel Marra area in Darfur region due to fighting between government forces and rebels.