"Chile is not only a threat to Bolivia but also to Peru," Morales said the day before the summit convened Tuesday.
Morales made the comment after Chile rejected Peru's claim to sea access along the Pacific coast, The Santiago Times reported.
Morales voiced his request for Bolivia's maritime access during his speech before the U.N. General Assembly last week.
Chilean Foreign Minister Alfredo Moreno said his country would abide by the Treaty of Peace and Friendship of 1904, which granted Chile sovereignty over territories Bolivia lost during the Pacific War, including the country's access to the sea.
Chilean President Sebastian Pinera said during the summit he was open to discussion.
"We will keep looking for paths to dialogue with Bolivia to find useful, concrete and plausible solutions for both countries," Pinera said. "This is the way forward, and I don't intend to ignore international treaties that are in full effect."
The organization's 22 Arab and 12 South American members are meeting to promote political and economical integration.