The AU's peace and security council met in Addis Ababa, the Ethiopian capital on Saturday, issuing a statement which expressed "strong conviction that the search for justice should be pursued in a way that does not impede or jeopardise efforts aimed at promoting lasting peace."
The council said it had been briefed on the ICC's plans by the court's deputy prosecutor, and "reiterated the AU's concern with the misuse of indictments against African leaders".
Luis Moreno-Ocampo, the ICC chief prosecutor, said on Thursday that a new case covering "crimes committed in the whole of Darfur over the last five years" would be opened on Monday, and that al-Bashir would be named as those linked to the violence in the region.
Moreno-Ocampo also said last month that Sudan's "entire state apparatus" was involved in an organised campaign to attack civilians in Darfur and said he would present judges with evidence implicating senior Sudanese officials in July.
Judges will probably take several weeks or months to rule on the likely application for new arrest warrants.
ICC judges had previously issued arrest warrants for Ahmad Harun, a government minister, and Ali Kushayb, a militia commander, but Khartoum has refused to hand them over.
In the event of an arrest warrant being issued, it will be the first bid before The Hague-based tribunal to charge a sitting head of state with war crimes.
Gary Grant, a barrister specialising in international law, told Al Jazeera that the legal proceedings will take effect when or if al-Bashir is deposed.
He said: "If someday, as I suspect will happen, the judges of the pre-trial chamber of the ICC agree to issue an arrest warrant, it will simply be an extant arrest warrant - it is not going to allow police officers to go in and arrest the sitting president."
"If al-Bashir is deposed, there is not going to be many places that he can go without being arrested ... and what sometimes happens is that the very fact of this arrest warrant may cause additional division within his government.
"What it may do is upset the status quo there, whereby former allies, desperate to do deals to avoid themselves being indicted, make efforts to depose the sitting president and hand him over to The Hague where he can be tried," he said.
"This obviously can have a great political effect, but legally, it is not going to bite while al-Bashir continues to sit comfortably in his presidential suite."
The UN says up to 300,000 people have died and more than 2.2 million have been displaced since the Darfur conflict broke out in February 2003. The Sudanese government disputes the figures saying 10,000 have been killed.
The conflict began when African ethnic minority fighters took up arms against the Arab-dominated government, which is alleged to have employed Arab militias to fight back.
Khartoum has condemned the ICC move as "criminal".
|Rebels call the ICC move a 'triumph for justice' [File:GALLO/GETTY]
"If you indict the head of state, the symbol of authority, the symbol of the dignity of the country, then it is a serious issue for us," Abdelhaleem Abdelmahmoud, Sudan's ambassador to the United Nations, told Al Jazeera.
"We condemn this criminal move by the prosecutor-general. It is very disastrous to the peace process, and to the efforts between the United Nations and Sudan to deal peacefully with the problem in Darfur.
"It is a very destabilising move," he said.
Abdelmahmoud also said that Sudan did not recognise the jurisdiction of the ICC and called the charges "politically motivated".
"It is one of the designs by the enemies of the country to settle political scores, they tried it through sanctions, they tried it through inciting our neighbours ... so it is a process of conspiracies against our country,' he said.
Sudan does not recognise the jursidiction of the ICC.
'Triumph for justice'
Khalil Ibrahim, leader of the the Justice and Equality Movement (Jem), the most powerful rebel group, said it was suspending all military operations until the announcement expected on Monday, to show its support for the ICC.
Jem came close to attacking Khartoum in May, the first time a rebel group brought one of Sudan's multiple civil wars near the capital. The clashes killed more than 200 and injured hundreds more.
Ibrahim said: "This is a happy day for humanity in the whole world, not only Darfur and Sudan.
"We are fully supporting the ICC if it happens that Bashir is at the top of their list."
Abdel Wahed Mohamed el-Nur, founder of the Sudan Liberation Movement (SLM), said: "This is a new world age - it will send a message that anyone who commits crimes and genocide will be judged."
The SLM Unity faction, which is separate from the SLM, also welcomed any ICC warrant for al-Bashir.
Sherif Harir, a senior SLM Unity commander, said: "This will show our mothers, sisters, brothers in the refugee camps that people care about them.
"Bashir has been killing us for so long. What more can he do? We are not afraid of any backlash."