The United States and China traded barbs Monday over the issue of the disputed South China Sea at the East Asia Summit which brought together 18 Asia-Pacific nations.According to diplomatic sources, U.S. national security adviser Robert O'Brien, who attended on behalf of U.S. President Donald Trump, stressed that China's claims of sovereignty over the sea are unacceptable.Chinese Premier Li Keqiang argued that if a conflict occurs in the South China Sea, the economic impact on China will be immeasurable, and called on and foreign countries not to increase tensions in the region. He was appa…READ FULL ARTICLE