Leaders of the 21-member Asia-Pacific Co-operation, APEC forum have pledged to move towards creating a regional free-trade area. The agreement was announced at the end of a two-day summit in Yokohama, Japan. The move would link the world's three biggest economies – the United States, Japan and China. The summit has been overshadowed by differences mainly between the US and China over currency valuations and trade imbalances. Washington wants to increase its own exports to the region, and believes China's cheap currency is a barrier to that goal. Chinese President Hu Jintao has said any change will only be made at Beijing's own pace.