The UN chief, facing Sudan's defiant president Monday, sharply denounced his government's expulsion of aid agencies in response to an international arrest warrant for him on charges of war crimes in Darfur. The address by UN Secretary-General Ban Ki-moon at the opening of an Arab League summit in Qatar highlighted the vast divide over Sudanese President Omar al-Bashir - with his Arab partners standing behind him and the backers of the International Criminal Court left widely powerless to bring him to justice if he remains in friendly territory. Monday's summit was the first time Ban and al-Bashir have come face-to-face since the ICC ordered his arrest on March 4, though it was unclear if they would have any direct contact. Ban told the 22-nation gathering that "we must also work together to transcend the tensions related" to the court, which was established at a UN conference in 1998. But there was little sign of compromise.