U.S. President Barack Obama (C) addresses leaders at a 10-nation Association of Southeast Asian Nations (ASEAN) summit in Rancho Mirage, California February 15, 2016. Obama is expected to press leaders from Southeast Asia to boost trade and back a common stance on the South China Sea. The leaders (L to R) Le Luong Minh, Secretary General of the Association of Southeast Asian Nations, Vietnam Prime Minister Nguyen Tan Dung, Thailand Prime Minister Prayuth Chan-ocha, Singapore Prime Minister Lee Hsien Loong, Philippine President Benigno Aquino, Laos President Choummaly Sayasone, U.S. President Barack Obama, Sultan of Brunei Hassanal Bolkiah, Cambodia Prime Minister Hun Sen, Indonesian President Joko Widodo, Malaysia Prime Minister Najib Razak and Myanmar Vice President U Nyan Tun. REUTERS/Mike Blake