VIENTIANE, Laos (AP) — President Barack Obama called off a planned meeting Tuesday with new Philippine President Rodrigo Duterte, seeking distance from a U.S. ally's leader during a diplomatic tour that's put Obama in close quarters with a cast of contentious world figures. It's unusual for one president to tell another what to say or not say, and much rarer to call the other a "son of a bitch." Duterte managed to do both just before flying to Laos for a regional summit, warning Obama not to challenge him over extrajudicial killings in the Philippines.