Al-Bashir is wanted by the International Criminal Court in the Netherlands for war crime allegations linked to the conflict in Sudan's western Darfur region.
The summit Trump is scheduled to attend Sunday, during his first overseas trip as president, is being organized by Saudi Arabia and will gather more than 50 top dignitaries from Muslim countries across Asia, Africa and the Middle East.
The Saudi officials who confirmed the meeting spoke on condition of anonymity because they were not authorized to speak to the media.