Earlier Sudanese officials expressed confidence that the AU would back al-Bashir.
"We expect the African Union's solidarity and condemnation of the indictment," Mutrif Siddig, a Sudanese foreign ministry official, said ahead of the meeting in Addis Ababa.
The AU meeting was called to discuss the attempt by Luis Moreno-Ocampo, the ICC prosecutor, to charge al-Bashir on suspicion of masterminding crimes against humanity in Sudan's western Darfur region.
Moreno-Ocampo accuses Bashir of orchestrating genocide that has killed 35,000 people outright, at least another 100,000 through "slow death" and forced 2.5 million from their homes.
Some analysts agree that the crisis over the court's demand could derail the fragile peace process in Africa's biggest country, but Khartoum has emphasised that it will pursue diplomacy rather than encouraging any violent backlash.
The AU's role is important because the UN resolution which referred Darfur to the international court in 2005 emphasised the need for co-operation with the bloc.
Tanzania, which currently chairs the AU, has already urged the court to suspend the move to arrest al-Bashir.
The Arab League has also criticised the court and Amr Mussa, the body's secretary general is in Khartoum, Sudan's capital, for talks on a plan to resolve the crisis.
Mussa said reception to his plan had been good but refused to divulge its details and stopped short of expressing total optimism that he could secure a solution.
"Well, I'm confident we can make progress," he said.
Al-Bashir's officials have been touring regional capitals to drum up support for Sudan's president.
Following a meeting with Sudan's envoys, Mwai Kibaki, Kenya's president, said that al-Bashir should not be "subjected to legal recourse in courts that may not have an understanding of the conflict".
Demonstrations against the ICC have been held almost daily in Sudan, with many war veterans protesting against the charges.
But they have been small and without the heavy government backing evident at some past demonstrations.
Following the prosecutor's request for a warrant to arrest al-Bashir, the UN has moved to raise security for its operations in the country, evacuate staff families and withdraw non-essential personnel.
Sudan has described the UN move as an overreaction.