Japanese Prime Minister Yukio Hatoyama (3rd L) gestures at the end of a photo session with leaders of the Mekong river region (L-R) Cambodian Prime Minister Hun Sen, Laotian Prime Minister Bouasone Bouphavanh, Myanmar Prime Minister Thein Sein, Thai Prime Minister Abhisit Vejjajiva and Vietnamese Prime Minister Nguyen Tan Dung at the State Guest House in Tokyo November 6, 2009. Japan is hosting its first summit with five South-East Asian countries on the Mekong River region.