Diplomatic efforts are being stepped up to try and improve security in the troubled western region of Darfur.
African Union troops are overstretched in Darfur
The Arab League and European Commission heads are having talks in the region.
African Union troops are struggling to monitor a peace deal and have been the focus of rebel attacks, but Sudan rejects allowing in UN peacekeepers.
More than 2m people have fled their homes and arrivals at displaced people's camps keep on coming, says the BBC's Karen Allen in Darfur.
Arab League Secretary-General Amr Moussa is in Khartoum for talks with President Omar al-Bashir, but Arab League members are divided about last month's UN Security Council resolution calling for the AU force to be replaced by UN peacekeepers.
The Security Council has approved sending a larger, better equipped UN peacekeeping force to protect civilians and guarantee the security of aid workers.
This would relieve the overstretched and under-funded 7,000-strong African Union force, but Sudan says it would compromise its sovereignty.
Sudan - itself an Arab League member - says its own army could establish security in Darfur if it had more regional support.
European Commission President Jose Manuel Barroso said during his visit to Darfur on Sunday, that both Sudan and the West must be flexible enough to find a workable formula to improve security.
"The humanitarian tragedy here is unlike any others," he told AP news agency in north Darfur.
"Here, almost everybody is fighting everybody."
Mr Barroso and 10 commissioners met AU leaders at their headquarters in Ethiopia to discuss how to help bolster the AU force.
"Under no circumstance can we leave Darfur without peacekeeping forces. But we know we must strengthen our forces," AU Commission Chairman Alpha Oumar Konare told reporters at the group's headquarters in Addis Ababa.
Our reporter says the AU troops, whose mission to Sudan was recently extended until December, have been caught up in the crossfire between a growing number of rival rebel groups.
Their vehicles, taken at gunpoint, limit their ability to patrol refugee camps.
In some areas of north Darfur the camps are virtually out of bounds to AU forces.
In one camp our reporter visited, 21 women had been raped in the past two weeks as they went out to gather firewood.
She says the AU commanders say the international community has let them down.
The meeting between the AU and the EU will also focus on other regional security issues like Somalia.
And the European Union will announce a $70 million support programme for the African Union.
The money will be spent on training and development and information technology. There will also be staff exchanges between the AU and EU.