An estimated 300,000 people have died in the Darfur conflict
The President of Sudan, Omar al-Bashir, has held talks with President Hosni Mubarak of Egypt on resolving the conflict in Darfur.
The meeting is part of efforts by Egypt to encourage negotiations between the Sudanese government and rebel groups.
Earlier, Egyptian officials met leaders of six guerrilla groups but the most powerful, the Justice and Equality Movement (Jem), did not attend.
The Darfur conflict is believed to have killed about 300,000 people since 2003.
Mr al-Bashir is wanted by the International Criminal Court for allegedly committing war crimes in the region.
Omar Qenawy, the deputy head of Egypt's information service, urged all of Sudan's competing groups and factions to "unite their viewpoints and their ranks", Egypt's official news agency, Mena, reported.
Before the talks began, Egyptian Foreign Minister Ahmed Aboul Gheit said his country had a strategic interest in helping to secure peace in Darfur.
"There may be friendly countries or the United Nations or regional countries which have interests and try to achieve peace and stability in Darfur, and this is something we support and push for," he said.
"But Egypt has shared borders with Sudan."
Bahar Idriss Abu Garda, leader of the United Resistance Front, one of the rebel groups attending the talks, said Egypt would "play a very important" unifying role in the coming days.
No representatives from Jem, Sudan's most active rebel group, attended the Cairo talks.
Qatar has been mediating separate peace talks between Khartoum and the Jem since February, but these were adjourned last month.