US President Barack Obama speaks during a press conference following the conclusion of the G20 summit in Hangzhou on September 5, 2016. (Photo: AFP)
Vientiane: U.S. President Barack Obama cancelled his first meeting with Philippines counterpart Rodrigo Duterte on Tuesday after the blunt-spoken Duterte described him as a "son of a bitch", casting a shadow over a gathering of Asian leaders in Laos.