* Mediator urges U.N. council to heed African Union
* Council urges Khartoum to let back aid groups (Recasts with speech by U.N./AU mediator, adds details)
UNITED NATIONS, March 26 (Reuters) - An International Criminal Court arrest warrant for Sudan's President Omar Hassan al-Bashir may have compromised the quest for peace in Darfur, a U.N. and African Union mediator said on Thursday.
The official, Djibrill Bassole, called on the U.N. Security Council to heed the concerns of the AU, an organization grouping 53 African countries that has urged the council to use its power to suspend the ICC's proceedings against Bashir.
Bashir was charged by the court with war crimes in Darfur.
Bassole was addressing the 15-nation council, which later appealed to Sudan to reconsider a decision to expel some aid groups in Darfur after the ICC move. Khartoum has accused the groups of supplying information to the ICC, which they deny.
Bassole, who represents the U.N. and AU jointly, said his task of bringing together Sudan's government and Darfur rebel groups for talks was "currently blocked by the intransigent positions of the warring parties" following the ICC move.
"In all likelihood, the process to find a political solution to the crisis in Darfur has been significantly slowed and even compromised," he told the closed-door meeting, according to a text of his speech seen by Reuters.
Bassole, a former Burkina Faso foreign minister, suggested the Security Council heed the African Union's position.
The AU and Arab League have urged the council to use its power under Article 16 of the ICC statute to defer court action. That call is backed by China and Russia, but Western states holding vetoes in the council have rejected it for now.
French Ambassador Jean-Maurice Ripert reaffirmed the Western view. "We respect the position of the African Union," he told reporters. "It doesn't mean we have to share the same position. ... We think that for the moment there is no reason to accept any Article 16 solution."
A LONG-RUNNING CONFLICT
The six-year conflict in Darfur, a region in western Sudan, has resulted in up to 300,000 deaths and the displacement of about 270,000 people, according to U.N. officials.
Darfur peace talks were held in Libya in October 2007, but fizzled out because key rebel groups boycotted them.
Last month, the Sudanese government and the Justice and Equality Movement (JEM), a major rebel group, agreed to meet for peace talks, but last week the JEM canceled the plan until Khartoum allowed back the aid groups it expelled.
Bassole said the rebels were contesting the legitimacy of Bashir and waiting to see what happened. He said it was important to try to save the peace process and expressed hope that the Sudanese ultimately would overcome their differences.
Khartoum ordered out 13 foreign groups and shut down three local ones after the ICC issued its warrant.
In a non-binding statement, the council said its members "stressed the importance of continuing the distribution of humanitarian assistance to all the needy in Darfur."
They urged Sudan's government "to continue cooperating with the United Nations and humanitarian organizations and appeal to it to reconsider the decision on suspending the activities of some non-government organizations in Sudan."
The statement was read to media by Ambassador Mohammed Abdel-Rahman Shalgam of Libya, this month's council president. Diplomats said it had been agreed to unanimously by all 15 council members, including Libya, a neighbor of Sudan, and China, which has been Sudan's chief ally on the council.
Bashir, defying the international arrest warrant, traveled to Libya on Thursday for talks with leader Muammar Gaddafi, Libya's government said.
It said they discussed the humanitarian situation in Darfur and would try to narrow the divisions between the Khartoum government and the U.N. mission in the region.
"The Sudanese government reiterated its willingness to accept new partners through agreement between Sudan and the United Nations," said the statement carried by Libyan state news agency JANA.
U.N. humanitarian chief John Holmes told the council that while efforts by remaining aid groups and Sudan's government "can plug some of the holes for the next few weeks" after the expulsions, "the cumulative effects over time ... significantly increase the risks to well over a million people."
But Sudan's envoy Abdalmahmoud Abdalhaleem told reporters, "The humanitarian situation is absolutely under control." (Additional reporting by Tom Pfeiffer in Rabat; Editing by Will Dunham)
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